NAFE11388_V04 NXP
Document overview
- Manufacturer or author: Provided By www.digicamel.com(free datasheet download site)
- PDF pages: 114
Technical content
Datasheet sections
- 1 General description
- 2 Features and benefits
- 3 Applications
- 4 Ordering information
- 4.1 Ordering options
- 4.2 Product family
- 5 Block diagram
- 6 Pinning information
- 6.1 Pinning
- 6.2 Pin description
- 7 Functional description
- 7.1 Overview
- 7.2 Precise and fast data acquisition
- 7.3 Detailed description
- 7.3.1 Architecture block diagram
- 7.3.2 High-voltage multiplexer — HVMUX
- 7.3.2.1 Analog input protection diodes and
- 7.3.2.2 HV input multiplexer - HVMUXIN
- 7.3.3 Programmable gain amplifier
- 7.3.3.1 PGA input operating ranges
- 7.3.3.2 PGA input common mode ranges
- 7.3.4 Low-voltage multiplexer - LVMUX
- 7.3.5 Analog-to-digital converter
- 7.3.5.1 ADC buffer
- 7.3.5.2 Sigma delta ADC
- 7.3.5.3 Frequency response
- 7.3.5.5 Step response
- 7.3.5.6 ADC data rate
- 7.3.5.7 Noise performance vs data rate
- 7.3.6 Gain and offset calibration
- 7.3.6.1 Gain and offset calibration coefficients
- 7.3.6.2 Factory calibrated coefficients
- 7.3.6.3 Loading and use
- 7.3.7 Temperature coefficient correction
- 7.3.8 Voltage reference
- 7.3.8.1 Low-drift voltage reference
- 7.3.8.2 Coarse voltage reference
- 7.3.8.3 Voltage reference selector
- 7.3.9 Temperature sensor
- 7.3.10 General-purpose input/output
- 7.3.11 Clock sources
- 7.3.11.1 Internal RC oscillator
- 7.3.11.2 Oscillator with external crystal
- 7.3.11.3 External oscillator
- 7.3.11.4 Clock selection
- 7.3.11.5 Auto-selection of clock source
- 7.3.11.6 User selection of clock sources
- 7.3.11.7 Clock period drift detection
- 7.4 Channel configuration and multichannel
- 7.4.1 Channel configuration
- 7.4.2 Working with multichannel sequencer
- 7.4.2.1 Channel enable
- 7.4.2.2 On-the-fly channel configuration
- 7.5 ADC Conversion and Reading modes
- 7.5.1 Reading start event
- 7.5.2 Reading process stop event
- 7.5.2.1 CMD_ABORT
- 7.5.2.2 CMD_END
- 7.5.3 Reading period
- 7.5.3.1 Calculate the effective reading period
- 7.5.3.2 Fastest reading period in SCCR mode
- 7.5.3.3 Effective output data rate with CH_DELAY
- 7.5.4 ADC synchronization
- 7.5.4.1 ADC_SYNC bit
- 7.5.4.2 Synchronize multi-NAFE with SYNC pulse
- 7.5.4.3 Synchronize NAFE to host with SYNC pin
- 7.5.4.4 Synchronize the host to the NAFE through
- 7.5.4.5 Synchronize the NAFE and host to the
- 7.5.4.6 Reading conversion start - SYNC pulse
- 7.5.5 Reading modes
- 7.5.6 Reading sequence
- 7.5.7 CMD_SS (single-channel single-reading)
- 7.5.7.1 Flow chart - SCSR
- 7.5.7.2 Timing diagram - SCSR
- 7.5.7.3 Code example - SCSR
- 7.5.7.4 Reading period for SCSR
- 7.5.8 CMD_SC (single-channel continuous-
- 7.5.8.1 Flow chart - SCCR
- 7.5.8.2 Timing diagram - SCCR
- 7.5.8.3 Code example - SCCR
- 7.5.8.4 Reading period for SCCR
- 7.5.9 CMD_MM (multichannel multireading)
- 7.5.9.1 Flow chart - MCMR
- 7.5.9.2 Timing diagram - MCMR
- 7.5.9.3 Code example - MCMR
- 7.5.9.4 Reading period for MCMR
- 7.5.10 CMD_MC (multichannel continuous-
- 7.5.10.1 Flow chart - MCCR
- 7.5.10.2 Timing diagram - MCCR
- 7.5.10.3 Code example - MCCR
- 7.5.10.4 Reading period for MCCR
- 7.5.11 CMD_MS (multichannel single-reading)
- 7.5.11.1 Flow chart - MCSR
- 7.5.11.2 Timing diagram - Flow chart - MCSR
- 7.5.11.3 Code example - Flow chart - MCSR
- 7.5.11.4 Reading period for MCSR
- 7.6 ADC code to voltage translation
- 7.7 Diagnostic features
- 7.7.1 Input under-range and over-range
- 7.7.2 REFH and REFL for diagnostic
- 7.7.3 Voltage supply rail monitoring
- 7.7.4 Thermal monitoring and thermal shutdown
- 7.7.5 Alarm
- 7.7.6 Interrupts
Universal ±25 V 8-Input Low Power AFE Rev. 4 — 2 April 2024 Product data sheet Document information Information Content Keywords NAFE11388, NAFE11348, 8-channel, analog front-end (AFE), 24-bit, 16-bit ADC resolution Abstract Highly configurable multichannel precision AFE for industrial applications.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
1 General description
The NAFE11388 is a highly configurable industrial-grade multichannel universal input analog front-end (AFE) that meets high-precision measurement requirements. The device integrates low-leakage, high-voltage (HV) fast multiplexers, low-offset and low-drift programmable gain amplifier (PGA) and buffers, high data-rate 24-bit Delta-Sigma analog-to-digital converter (ADC), and low-drift voltage reference. All of the HV analog pins are diode-protected internally for electromagnetic compatibility (EMC) and miswiring scenarios. The NAFE11388 is equipped with various diagnostic and supplies supervisory circuitry for condition monitoring and anomaly detection. Two precise calibration voltage sources are made available for ease of end-to-end system self- calibration and predictive maintenance. The NAFE11388 family of products is designed for programmable logic controllers (PLCs), I/O modules, data loggers, instrumentation, and high-precision sensor and data acquisition systems. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
2 Features and benefits
- Eight configurable HV inputs – Single-ended or differential, with ranges up to ±25 V – Independent configurations for voltage and current ranges – Overvoltage protected up to ±36 V for less than one hour
- Fast data rates – 7.5 SPS to 288 kSPS – Simultaneous 50 Hz/60 Hz line rejection – ENOB: 17-bit at 72 kSPS
- High accuracy – 0.005 %FS accuracy at room after user calibration – 0.1 %FS accuracy over -25 ℃ to 105 ℃
- System calibration – End-to-end calibration with integrated precise voltage sources – Accurate factory-calibrated products available
- ±3 ⁰C internal temperature sensor
- 0.2% internal oscillator accuracy at room temperature
- Diagnostic system for faults detection and prediction
- CRC error detection
- Ten GPIOs
- 32 MHz SPI interface
- Robust 7.5 kV HBM ESD and IEC61000-4-5 2 kV surge protection
- Power supply: HV: ±7 V to ±24 V, LV: 3.3 V
- 125 mW low power consumption
- Operating temperature range TA: -40 ℃ to +125 ℃
- Package: 64 pin, 9 mm x 9 mm x 0.85 mm HVQFN NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
3 Applications
- Data acquisition system
- PLC, DCS I/O modules
- Industrial automation and process control NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
4 Ordering information
Table 1. Ordering information
4.1 Ordering options
1000 TA = -40 °C to +125 °C
260 TA = -40 °C to +125 °CNAFE11388B40BS
1300 TA = -40 °C to +125 °C
260 TA = -40 °C to +125 °CNAFE11348B40BS
260 TA = -40 °C to +125 °CNAFE11148B40BS
Table 2. Ordering options
4.2 Product family
offloading the host processor to achieve higher performance and low power consumption of overall system. scalable applications of analog I/O modules and data acquisition systems. representative to get further information and availability of appropriate configurations. Table 3. Part numbers NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
5 Block diagram
Figure 1. Block diagram NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
6 Pinning information
6.1 Pinning
Figure 2. Pin configuration in 64-lead 9 mm x 9 mm x 0.85 mm VQFN package NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
6.2 Pin description
9 AGND Ground Analog ground
14 AGND Ground Analog ground
16 AGND Ground Analog ground
exposed pad) Zener to AGND for protection.
18 AGND Ground Analog ground
19 AGND Ground Analog ground
20 AGND Ground Analog ground
21 AVDD Supply 3.3 V analog power supply, 0.1 µF || 4.7 µF cap to AGND.
22 AGND Ground Analog ground
23 REF_BYP AO Buffered voltage reference bypass, 100 pF (max loading) cap to AGND
27 AGND Ground Analog ground
28 CAPP_ADC AO ADC buffer positive output, 1 nF C0G cap to CAPN
29 CAPN_ADC AO ADC buffer negative output, 1 nF C0G cap to CAPP
33 AGND Ground Analog ground
34 AGND Ground Analog ground
36 RSTB DI Chip reset, active-low (CMOS push-pull or open drain with internal 100 kΩ pullup). 37 SPI_ADDR DI SPI address 0 (with internal 100 kΩ pulldown). Table 4. Pin description NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
38 DGND Ground Digital ground
39 INTB DO Active low interrupt output (CMOS push-pull or open drain internally pulled up)
40 SYNC DI ADC sync pulse input
41 CSB DI Chip select input, active-low (with internal 100 kΩ pullup)
42 SCLK DI SPI clock input
43 MOSI DI SPI data input
44 MISO DO SPI data output
45 DRDY DO ADC data ready output, active-high
46 DVDD Supply 3.3 V digital power supply, 0.1 µF || 4.7 µF cap to DGND.
47 DGND Ground Digital ground
48 LDO_DIG AO Internal 1.8 V LDO bypass, 0.1 µF || 4.7 µF uF cap to DGND.
51 DGND Ground Digital ground
52 GPIO9 DI, DO General-purpose digital input/output or system clock output
53 GPIO8 DI, DO General-purpose digital input/output
54 GPIO7 DI, DO General-purpose digital input/output
55 GPIO6 DI, DO General-purpose digital input/output
56 GPIO5 DI, DO General-purpose digital input/output
57 DVDD Supply 3.3 V digital power supply, 0.1 µF || 4.7 µF cap to DGND.
58 DGND Ground Digital ground
59 GPIO4 DI, DO General-purpose digital input/output
60 GPIO3 DI, DO General-purpose digital input/output
61 GPIO2 DI, DO General-purpose digital input/output
62 GPIO1 DI, DO, AI General-purpose digital I/O or ADC differential analog input: GPIO0-GPIO1
63 GPIO0 DI, DO, AI General-purpose digital I/O or ADC differential analog input: GPIO0-GPIO1
64 AGND Ground Analog ground
Table 4. Pin description...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7 Functional description
7.1 Overview
The NAFE11388 is a highly configurable, universal eight-input AFE with various integrated diagnostic features. At HV analog inputs, the low-leakage pins could be configured anywhere from eight single-ended to four differential signals, with external common input AICOM or internal AGND reference. Three selectable PGA gain settings of 0.2 V/V, 0.4 V/V, and 0.8 V/V are available to provide differential full ranges of ±25 V to ±6.25 V. In general, all of the HV input characteristics are specified to the linear (nominal) input ranges for all of the channel gain settings, which is 80 % of the full input range. In addition to the differential signals at PGA output, one auxiliary differential input GPIO0-GPIO1, four low-voltage diagnostic signals are also multiplexed to ADC: power supplies AVDD, HVDD, HVSS, and an independent coarse voltage reference (REF_coarse). The voltage reference (VREF) derived voltage sources REFH and REFL are available through pins for external measurement. These two voltage sources are also connected as inputs to high-voltage multiplexer (HVMUX). They could be used for on-chip self-calibration or self-diagnostic purposes, regardless of the voltage reference sources, which can be either external, internal, or mixed. When supplied with the factory-calibrated coefficients, REFH and REFL facilitate routine calibrations without the need for additional accurate components. An independent on-chip temperature sensor is included for continuous die temperature monitoring with a 16-bit readout. This temperature reading is also used to trigger an overtemperature warning at 145 ⁰C, auto-shutdown at 165 ⁰C, or the user-programmable temperature alarm. The NAFE11388 comes with ten GPIOs that satisfy most of the needs for monitoring and control in typical applications. The selectable clock sources could be either the internal oscillator or a crystal oscillator, or external clock. In addition, a data and conversion synchronization is available via SYNC and DRDY pins, and the last falling edge of the SPI clock. Succeeding to 24-bit ΔΣ modulator, a multistage digital filter was designed to offer a wide range of data rates with a selectable cascade of SINC filters and the option of Single-Cycle Settling mode versus Normal Settling mode. In multichannel, fast-switching applications, the user may trade off speed/accuracy and fine-tune the effective data rate. Simultaneous 50 Hz and 60 Hz line rejection is available in lower data rates. The software-configurable sequencer enables high data-rate input channel scanning at system level. Five efficient reading modes are available for ADC data conversion: single-channel single-reading (SCSR), single-channel continuous-reading (SCCR), multichannel single-reading (MCSR), multichannel multireading (MCMR), and multi-channel continuous-reading (MCCR). The user may issue command CMD_BURST_DATA to read back multiple channels data in a single SPI transaction. See Table 18 for conversion start commands.
7.2 Precise and fast data acquisition
The NAFE11388 is suitable for data acquisition of high-precision and high-speed analog inputs. The NAFE11388 integrates an input multiplexer (MUX), high gain bandwidth (GBW) programmable gain amplifier (PGA), and a high-resolution 24-bit sigma-delta ADC. The optimized architecture of the MUX, PGA, and ADC provides fast input-scanning with flexible output data rates, which are comparable with SAR ADC architecture used in fast response-time system. Programmable ADC output data rate range:
- 288 ksps to 7.5 sps in Normal Settling mode
- 72 ksps to 1.5 sps in Single-Cycle Settling mode Figure 3 shows the scanning time required when HV MUX switches from one input to another (effectively presenting a step function), and PGA follows to settle with limited bandwidth and the required ADC conversion time at a specified data rate. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
Figure 3. Scanning time per input
7.3 Detailed description
This section describes the building blocks integrated in the NAFE11388.
7.3.1 Architecture block diagram
ADC, digital calibration, voltage reference, and clock sources as shown in Figure 1.
7.3.2 High-voltage multiplexer — HVMUX
The high-voltage analog input section serves as an externally accessible input and internal input.
- AI1P, AI2P, AI3P, AI4P are connected to the positive high-voltage multiplexer HVMUXINP input.
- AI1N, AI2N, AI3N, AI4N are connected to the negative high-voltage multiplexers HVMUXINN input. AICOM, REFH, REFL, and AGND (internal ground) are connected to both positive and negative high-voltage input multiplexers HVMUXINP and HMMUXINN, respectively.
7.3.2.1 Analog input protection diodes and clamping
electrostatic discharge (ESD) and surge protection. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
29 V DC CLAMP
Figure 4. Input pins protection Each HV input pin is equipped with input protection diodes connected to HVDD, HVSS. for each HV input pin for reliability. See Section 11.1. from ESD events occurring during the manufacturing process and during printed-circuit board (PCB) assembly. 2.5 kΩ or greater external series resistor is required to limit the input current to the specified value.
7.3.2.2 HV input multiplexer - HVMUXIN
and the negative wire of signal to AICOM. canceled and the effective output data rate is half of the programmed value. AICOM or GND while AIxN input is AI1N..AI4N, REFH, REFL. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.3.2.2.1 Analog common input (AICOM)
To ensure precise single-ended measurements, AICOM pin should be connected in series with a 2.5 kΩ resistor and connected to an external GND reference physically close to the measured positive signal on the printed- circuit board (PCB).
7.3.2.2.2 REFH and REFL
REFH and REFL provide stable and accurate voltage sources derived from VREF_BYP. REFH and REFL are 92 % and 8 %, of VREF_BYP, with a nominal value of 2.3 V and 0.2 V, respectively. REFH and REFL are connected to inputs of both HVMUXINP and HVMUXINN multiplexer. REFH and REFL could be used for system-level self-calibration on the field, failure prediction, and predictive maintenance. Factory OPT_COEF1 and OPT_COEF2 is available for REFH and REFL on optional part numbers.
7.3.2.2.3 Low-leakage circuit
The NAFE11388 provides a high-input impedance of 1 GΩ and low-input leakage current less than 5 nA at 105 °C. In combination with its low-noise and low-offset drift PGA, the device is well-suited for precision temperature measurement with RTD and TC.
7.3.3 Programmable gain amplifier
The programmable gain amplifier (PGA) is a low-noise, programmable gain, differential input, differential output amplifier. The PGA operates in Gain or Attenuation mode, depending on the gain selected. Typically, the PGA is programmed to utilize the input range of the ADC to the full-scale input signal. Available PGA gains are 0.2, 0.4, 0.8 V/V. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.3.3.1 PGA input operating ranges
different types of input signals and PGA gain setting. Table 5. HV input ranges and resolutions NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.3.2 PGA input common mode ranges
PGA input common mode voltage range depends on PGA gain.
7.3.4 Low-voltage multiplexer - LVMUX
are routed to the ADC input via a low-voltage multiplexer controlled by register bit HVSEL. LVSIG_IN = 3 (VADD), the setting for CH_CONFIG0 is 0xCC07 when CH_GAIN = 0 and TCC_OFF = 1. Table 6. CONFIG0 Setting for using LVMUX signals
7.3.5 Analog-to-digital converter
7.3.5.1 ADC buffer
CAPN, are to be loaded with external C0G type capacitor.
7.3.5.2 Sigma delta ADC
configurable digital filter. between resolution, data rate, and line-cycle rejection acceptable in a system. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
sps. The low-speed stage is a programmable-order SINC filter as SINC1, SINC2, SINC3, SINC4. The data rate is programmed by the CH_CONFIG1.ADC_DATA_RATE bits. The digital filters are controlled by CH_CONFIG1.ADC_SINC bits. the NAFE11388 offers two different Conversion modes. Settling mode is suggested for single channel to get a faster data rate or lower noise.
7.3.5.3 Frequency response
The low-pass filtering effect of the SINC filters sets the overall frequency response of the ADC. stage (SINC1, SINC2, SINC3, SINC4). rate 3000 sps with second stage SINC4 filter. Figure 5. SINC filter transfer function Figure 6 shows the frequency responses of the second stage SINC1, SINC2, SINC3, and SINC4 filter. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 6. Second stage SINC filter transfer function The NAFE11388 features a digital filter that provides a 50 Hz and 60 Hz Normal mode rejection (NMR). Figure 7 shows the SINC4 filter NMR at the date rate of 10 sps, 50 sps, and 60 sps. Figure 7. SINC Normal mode rejection vs frequency vs data rata
7.3.5.5 Step response
- Normal settling: Fits better for single-channel reading, providing lower noise measurements.
- Single-cycle settling: Fits better for multichannel reading, providing settled output. Figure 8 shows the relative settling time of the digital filter for the normal settling for different orders of SINC filter. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
8 SINC_1
Figure 8. SINC filter step response Figure 9. Normal Settling mode and SINC4 transition from low to high, the output takes one sample to settle. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 10. Single-Cycle Settling mode and SINC4
7.3.5.6 ADC data rate
Table 7 shows the programmable data rates for different SINC digital filters and Settling modes. ADC_DATA_OUT_16BIT bit in SYS_CONFIG0 register. Table 7. Data rate (system clock: 4.608 MHz) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
SINC4 only in Normal Settling mode.
7.3.5.7 Noise performance vs data rate
equivalent noise bandwidth, which results in lower noise. ranges of ±25 V to ±6.25 V) as input-referred values. The noise performance data are in units of μVRMS (RMS = root mean square) under the conditions listed. The following tables in this section report the noise performance versus data rate and PGA gain setting. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.5.7.1 Noise 24-bit option
Table 8. Noise µVrms (24-bit low power) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.5.7.2 ENOB 24-bit option
Table 9. ENOB 24-bit option NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.5.7.3 Noise 16-bit option
Table 10. Noise μVrms (16-bit low power) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.5.7.4 ENOB 16-bit option
Table 11. ENOB (16-bit low power) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.3.6 Gain and offset calibration
- Gain: GAIN_COEF0[23:0] to GAIN_COEF15[23:0]
- Offset: OFFSET_COEF0[23:0] to OFFSET_COEF15[23:0]
- Optional: OPTC_COEF0[23:0] to OPTC_COEF13[23:0] To reduce the calibration error, the bit-width of gain, offset, and self-calibration coefficient registers are 24-bit wide, the same as main ADC. The above user-calibration coefficients can be read and written by the user. During device power up or reset, the factory calibrated coefficients stored in NVM are loaded into the preset registers, if available. The user may overwrite with different calibration coefficients as needed. In general, there are three categories of calibration coefficients:
- System offset and gain calibration coefficients for voltage or current input
- System offset and gain calibration coefficients for resistance and RTD input
- Self-calibration values – 2.5 V VREF – 2.3 V REFH and 0.2 V REFL These features enable accurate dynamic self-calibration without external voltage sources and advanced predictive maintenance. Table 12 describes the calibration gain/offset coefficient pair, addressable by coefficient pointer CH_CONFIG1.CH_CAL_GAIN_OFFSET. Note: The gain and offset coefficients are channel-gain setting dependent. Pointer Gain register ADDR \\h Offset register ADDR \\h NVM stored coefficient and setting 0 GAIN_COEF0[23:0] 80 OFFSET_COEF0[23:0] 90 Gain = 0.2 V/V, single-ended AIxx-AICOM 1 GAIN_COEF1[23:0] 81 OFFSET_COEF1[23:0] 91 Gain = 0.4 V/V, single-ended AIxx-AICOM 2 GAIN_COEF2[23:0] 82 OFFSET_COEF2[23:0] 92 Gain = 0.8 V/V, single-ended AIxx-AICOM
3 GAIN_COEF3[23:0] 83 OFFSET_COEF3[23:0] 93 -
4 GAIN_COEF4[23:0] 84 OFFSET_COEF4[23:0] 94 -
5 GAIN_COEF5[23:0] 85 OFFSET_COEF5[23:0] 95 -
6 GAIN_COEF6[23:0] 86 OFFSET_COEF6[23:0] 96 -
7 GAIN_COEF7[23:0] 87 OFFSET_COEF7[23:0] 97 -
8 GAIN_COEF8[23:0] 88 OFFSET_COEF8[23:0] 98 -
9 GAIN_COEF9[23:0] 89 OFFSET_COEF9[23:0] 99 -
10 GAIN_COEF10[23:0] 8A OFFSET_COEF10[23:0] 9A -
11 GAIN_COEF11[23:0] 8B OFFSET_COEF11[23:0] 9B -
12 GAIN_COEF12[23:0] 8C OFFSET_COEF12[23:0] 9C -
13 GAIN_COEF13[23:0] 8D OFFSET_COEF13[23:0] 9D -
14 GAIN_COEF14[23:0] 8E OFFSET_COEF14[23:0] 9E -
15 GAIN_COEF15[23:0] 8F OFFSET_COEF15[23:0] 9F -
Table 12. System gain and offset calibration registers NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 13. Optional calibration registers
7.3.6.1 Gain and offset calibration coefficients
multiplier for offset and gain compensation. 00_0000\\h has no offset correction. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 14. Gain calibration coefficient and factor Table 15. Offset calibration coefficient and factor
7.3.6.2 Factory calibrated coefficients
to the user-calibration coefficients registers. accessible, the user may shuffle the location of the calibrated coefficient pairs as necessary. coefficient pair to be used for each channel setup. GAIN_COEF15(at 0x8F) is paired with OFFSET_COEF15(at 0x9F).
7.3.6.3 Loading and use
SYS_STATUS0 register is asserted to 1, that indicates the chip is ready to perform conversion. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE For ADC conversion on the logical channel (default is channel 0, CH0), a pair of offset and gain coefficients is mated with each logical channel by register CH_CONFIG1.CH_CAL_GAIN_OFFSET[3:0]. Before the conversion takes place, the value in the designated pair of offset and gain coefficient will be latched into the internal registers to be used for compensating internal gain and offset errors. The user may shuffle GAIN_COEF and OFFSET_COEF when setting up the logical channel after initialization or power up. For example, setting channel CH0 to gain = 0.8 V/V, the user will need to set GAIN_COEF0[23:0] and OFFSET_COEF0[23:0] with the calibrated coefficient to gain = 0.8 V/V and so forth. See Table 12 for the stored location of each gain- dependent coefficients. The selected channel for read/write register configuration is indicated by using the pointer position. The position is displayed in bit CONFIG_CH_PTR[3:0]. Similarly, the active ADC conversion on channel-pointer position is shown in bit ADC_CONV_CH[3:0] SPI command CMD_RELOAD will reload the factory calibrated coefficients from internal non-volatile memory into registers GAIN_COEF, OFFSET_COEF and SELF_CAL_COEF. This will overwrite previously modified values. When CMD_RELOAD is issued, the status bit SYS_STATUS0.CHIP_READY will be deasserted. It will then be asserted when NVM data reloading is complete.
7.3.7 Temperature coefficient correction
TCC_OFF = 0 enables a temperature coefficient correction that reduces the temperature drift error. Set this bit to 1 to disable the TCC feature for any of the following three situations:
- REF_EXT is used
- The ratiometric measurement is used with internal reference (SYS_CONFIG0.REF_SEL[1:0] = 00h)
- The following input signals are used: REFH (= VREF*0.92), REFL (= VREF*0.08)
7.3.8 Voltage reference
7.3.8.1 Low-drift voltage reference 1
The NAFE11388 integrates a voltage reference with calibrated TCC coefficients to reduce the drift error over temperature. Set register bits TCC_OFF = 0 to apply TCC coefficients for non-ratiometric measurement. If external voltage reference is used as ADC reference, set TCC_OFF = 1.
7.3.8.2 Coarse voltage reference 2
The NAFE11388 includes a second and independent internal coarse voltage reference for diagnostic purpose.
7.3.8.3 Voltage reference selector
The voltage reference selector enables the selection of either internal or external reference, or a combination of internal and external reference by setting register bits REF_SEL[1:0]. External 2.5 V voltage reference is applied at REF_EXT pin when required. See Table 30.
7.3.9 Temperature sensor
The NAFE11388 includes a temperature sensor to monitor the IC junction temperature and provides temperature alarm with user-programmable threshold. Overtemperature warning and shutdown factory defaults are 145 ℃ and 165 ℃, respectively. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.3.10 General-purpose input/output
GPIO0..9 are configured as GPIO. Figure 11. General-purpose input/output GPI_DATA (0x29\\h): Read (R) only register. It detects input logic level signal at the corresponding pin. GPIO_CONFIG0 (0x2A\\h): Read/Write (R/W) GPO_EN register. It enables an output path. or input function as programmed by user. looping back from GPO_DATA register and/or GPIO edges detection. for positive and GPI_EDGE_NEG(0x2E) for negative, respectively, are implemented as follows. writing 1 to the bit that is set to 1 (W1C) by the previous event. Some GPIOs, such as GPIO0, GPIO1, GPIO2, and GPIO9 serve dual functions. voltage range is from 0.5 V to 2.5 V. SYS_CONFIG0.MCLK_OUT_ENABLE. GPIO2 can provide CRC_ERROR status flag by writing '1' to SYS_CONFIG0.CRC_EN.
7.3.11 Clock sources
sources: internal RC oscillator, oscillator with external crystal, external oscillator. Figure 12 shows the clock architecture. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 12. Clock architecture
7.3.11.1 Internal RC oscillator
support of any external clock source. The internal oscillator nominal frequency is 18.432 MHz.
7.3.11.2 Oscillator with external crystal
7.3.11.3 External oscillator
require synchronization between the NAFE11388 and the host, as well as coherent sampling of the input signal. The external oscillator should be applied to pin EXTCLK/XI.
7.3.11.4 Clock selection
- Auto-selection upon power on
- User selection via system register configuration
7.3.11.5 Auto-selection of clock source
upon power up and switches over to the available clock source. SRC_SEL[1:0] to 2’b10. Detection is complete at this point with the external clock used as the system clock. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
the SRC_SEL[1:0] to 2'b11. Detection is complete at this point with the external crystal set as the system clock. CLK_DET_DONE = 1, the internal digital CHIP_RDY is asserted to 1.
7.3.11.6 User selection of clock sources
selected by writing to the clock source system configuration register. NAFE11388 maintains the previous clock configuration.
7.3.11.7 Clock period drift detection
difference between the external clock and internal RC Oscillator. whenever the EXTCLK is over the 20 % period difference.
7.4 Channel configuration and multichannel sequencer
7.4.1 Channel configuration
Figure 13. Logical channel structure NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
- Channel configuration registers: CH_CONFIG0, CH_CONFIG1, and CH_CONFIG2. – CH_CONFIG0 (0x20\\h) – Select input channel, either high voltage (HV_AIP/HV_AIN, HV_SEL=1) or low voltage (LVSIG_IN[2:0], HV_SEL = 0). – Select one of the eight channel gains if high-voltage input is selected. – Disable/enabled the channel temperature coefficients correction (TCC_OFF = 1). – CH_CONFIG1 (0x21\\h) – Set the pointer (CH_CAL_GAIN_OFFSET[3:0]) to select one of the 16 calibrated gain and offset coefficient pairs in the calibrated channel coefficient registers: GAIN_COEF0…15 and OFFSET_COEF0…15. – Set the pointer (CH_THRS[3:0]) to select one of the 16 channel over- and under-range threshold pairs: CH_CONFIG5.OVR_THRS0…15 and CH_CONFIG6.UDR_THRS0…15. – Select one of 29 possible data rates: ADC_DATA_RATE[4:0]. – Select one of the five possible filter options for second-stage SINC filter: ADC_SINC[2:0]. – CH_CONFIG2 (0x22\\h) – Select one of the 64 possible preset channel delays before ADC start conversion: CH_DELAY[5:0]. – Select ADC Settling mode, single-cycle, or normal: ADC_NORMAL_ SETTLING. – Select to reset ADC digital filters at the start of every ADC conversion: ADC_FILTER_RESET. – Select to enable input channel level chopping with two ADC conversions (Precision mode): CH_CHOP =
- Channel gain coefficients: GAIN_COEF0..15 [23:0] (0x80 – 0x8F) – These 16 24-bit calibrated gain coefficients are used to correct the gain error for the selected logic channel. The uncalibrated default is equivalent to 1 V/V.
- Channel offset coefficients: OFFSET_COEF0..15[23:0] (0x90 – 0x9F) – These 16 24-bit calibrated offset coefficients are used to correct the offset error for the selected logic channel. The uncalibrated default offset value is 0 V.
- Channel input range detect threshold – CH_CONFIG5 (0x50..0x5F): Over-range 24-bit threshold setting These 16 24-bit registers are used to set the over-range threshold values. – CH_CONFIG6 (0x60..0x6F): Under-range 24-bit threshold setting These 16 24-bit registers are used to set the under-range threshold values.
- Channel output data – CH_DATAi[23:0]: Holds ADC converted output data as selected by CMD_CHi. CH0 data is address 0x40 and CH15 data address is 0x4F.
- Channel status – CH_STATUS0[i]: Over-range status bit. CH0 status is in bit[0] and CH15 is in bit[15]. – CH_STATUS1[i] - Under-range status bit. CH0 status is in bit[0] and CH15 is in bit[15]. Upon startup, chip reset, and register clear, each of the logical channels is to be reconfigured once. Channel gain/offset coefficients are preloaded from the on-chip NVM after POR. The user could overwrite these coefficients after the POR. Channel select, CMD_CHi :
- SPI command CMD_CHi is used to select the logic channel CHi, and the CH_DATAi, where i = 0..15 is the channel index.
- Channel configuration is activated after the conversion command is issued.
- The activated logical channel is indicated by reading CONFIG_CH_PTR[3:0] in SYS_STATUS0 register. For single-channel conversion, the host will issue (CMD_SS, CMD_SC), then wait for DRDY signal asserted high where ADC data is ready for the host to read. Figure 14 shows a typical sequence before CMD_SS or CMD_SC is issued. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
enabled logical data channel(s). enabled logical data channel(s). Figure 14. Steps to setup for single-channel conversion reading setup and the conversion result will be stored at CH_DATA5. Example how to select, config, enable, run, read data. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE write_reg16("CH_CONFIG1", {CH_CAL_GAIN_OFFSET, CH_THRS, ADC_DATA_RATE, ADC_SINC} ); write_reg16("CH_CONFIG2", {CONV_DELAY, ADC_SINGLE_NORMAL, ADC_FILTER_RESET ,CH_CHOP,7’b000_0000}); write_cmd_ss() ; // CMD_SS – issue single ADC conversion command wait_rise_edge (DRDY); CH_DATA5 = read_reg24(“CH_DATA5”); // read the conversion data at logical channel 5
7.4.2 Working with multichannel sequencer
The sequencer will step through CH0 to CH15 (or current channel to CH15) to execute the enabled channels (CH_CONFIG4.MCH_EN[15:0]) and store ADC output in the corresponding ADC_DATA output register (CH_DATA0..CH_DATA15). ADC conversion can be set either to Single-Cycle Settling mode or Normal Settling mode with CH_CONFIG4.ADC_SINGLE_NORMAL = 0 or 1, respectively. However, single-cycle settling is typically preferable in many applications. When CMD_MM or CMD_MC command is issued, the sequencer will begin ADC conversions on the enabled channels and stop upon completing the conversion of the last enabled channel. At the end of the Sequencer mode, SYS_STATUS0.ADC_CONV_CH[3:0] is set to CH0. The DRDY pin will transition from 0 to 1 when ADC_DATA is ready for the host to read. The register SYS_STATUS0.ADC_CONV_CH[3:0] can be used for tracking the current ADC channel. ADC busy status is indicated in either status bit SYS_STATUS0.SINGLE_CH_ACTIVE or SYS_STATUS0.MULTI_CH_ACTIVE. sequencer with the use of SYNC pulse and reading command as triggers. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
enabled logical data channel(s). enabled logical data channel(s). for enabled logical channel(s). for enabled logical channel(s). Figure 15. Steps to setup for multichannel conversion reading
7.4.2.1 Channel enable
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE When single-conversion, single-reading (CMD_SS) or single-conversion continuous-reading (CMD_SC) is used, channel enable CH_CONFIG4[15:0] is ignored. This register is only used in multichannel reading, sequencer conversions. MCH_EN = 0xFFFF, all 16 channels are enabled in multichannel sequencer conversions.
7.4.2.2 On-the-fly channel configuration
Any of the 16 logical channels are configurable on-the-fly and could be modified while the sequencer is running. Note: Any register setting changes on ADC active channel (SINGLE_CH_ACTIVE or MULTI_CH_ACTIVE) will not be taken into effect until next ADC conversion command CMD_ is issued.
7.5 ADC Conversion and Reading modes
The NAFE11388 reading process starts when a start event is received, and finishes with an event that signals the completion of reading. The reading process includes four main steps: 1. Reading start event received. 2. Wait a period equal to the configured programmable delay. 3. Execute one or more analog-to-digital conversions. 4. Send the DRDY signal when the reading process is complete.
7.5.1 Reading start event
The NAFE11388 provides two types of reading start event to fit simplicity and performance. One reading event is command based. It is intrinsic in the SPI command transaction. The other is triggered through SYNC pin. The SPI reading process starts on the last falling edge of the SPI command clock. The SYNC reading process begins on the rising edge of the SYNC pulse at the SYNC pin.
7.5.2 Reading process stop event
The reading process can be stopped by the host issuing either SPI commands or a SYNC pulse. This command is useful if the host wants to stop an infinite reading process executed autonomously by the NAFE11388. The SPI commands to stop reading in progress are CMD_ABORT or CMD_END.
7.5.2.1 CMD_ABORT
While the NAFE reading period is active and the ADC is converting, if a CMD_ABORT command is received, the ongoing conversion is aborted, and the device returns to its initial waiting state. The corresponding CH_DATA register will not be updated.
7.5.2.2 CMD_END
While the NAFE reading period is active and the ADC is converting, if CMD_END is received, ADC conversion is allowed to complete (contrary to CMD_ABORT) and CH_DATA register is updated with new results before device returns to its initial waiting state.
7.5.3 Reading period
The reading period is defined as the time interval between the reading start event and the reading end event. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
If SYS_CONFIG0.ADC_SYNC = 0, the conversion start event is the last falling edge of the SPI command clock. completion event is the rising edge of the DRDY signal. The reading period is a function of system clock, reading mode, fixed delay, data rate and programmable delay. Also, the fixed delay is different for the first reading and the readings after first reading.
- Single-channel single-reading (SCSR)
- Single-channel continuous-reading (SCCR)
- Multichannel single-reading (MCSR)
- Multichannel multireading (MCMR)
- Multichannel continuous reading (MCCR) The system clock frequency is 4.608 MHz. The period of system (T_sys_clk) is 1/(4.608 MHz) = 217 ns with the master clock at 18.432 MHz. Master clock 18,432,000 System clock 4,608,000 Prog delay code Prog delay (# sysclk) Programmable delay(s) 0 0 000.000E+0 1 2 434.028E-9 2 4 868.056E-9 3 6 1.302E-6 4 8 1.736E-6 5 10 2.170E-6 6 12 2.604E-6 7 14 3.038E-6 8 16 3.472E-6 9 18 3.906E-6 10 20 4.340E-6 11 28 6.076E-6 12 38 8.247E-6 13 40 8.681E-6 14 42 9.115E-6 15 56 12.153E-6 16 64 13.889E-6 17 76 16.493E-6 18 90 19.531E-6 19 128 27.778E-6 20 154 33.420E-6 21 178 38.628E-6 22 204 44.271E-6
Table 16. Channel programmable delay NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 16. Channel programmable delay...continued
7.5.3.1 Calculate the effective reading period
reading period examples are provided in the Reading mode sections.
7.5.3.2 Fastest reading period in SCCR mode
7.5.3.3 Effective output data rate with CH_DELAY
Table 17 shows examples of the most common reading periods. Table 17. Popular reading periods NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 17. Popular reading periods...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.4 ADC synchronization
- Synchronize multi NAFE with SYNC pulse at SYNC pin
- Synchronize the NAFE to host for conversion start by SYNC pulse
- Synchronize the host to the NAFE through DRDY signal
- Synchronize the NAFE and the host clock to the same clock, by one of the following methods: – Configure the NAFE to use external clock and apply 18.432 MHz clock pulses at EXTCLK/XI pin – Configure the NAFE to output its system clock to GPIO9
7.5.4.1 ADC_SYNC bit
Conversion mode. The conversion start is only triggered by a rising edge at the SYNC pin. SYS_CONFIG0.ADC_SYNC is set to 1.
- Select the Reading mode
- Trigger the conversion start The conversion start with SYNC pulse is supported in all Reading modes. Table 18 summarizes the Reading mode and start commands. Conversion start trigger ADC_SYNC = 0 ADC_SYNC =1 SCSR CMD_SS SYNC pin SCCR CMD_SC SYNC pin MCSR CMD_MS SYNC pin MCMR CMD_MM SYNC pin Reading modes MCCR CMD_MC SYNC pin Trigger event on CMD_xy is the last SPI command falling edge check Trigger event on SYNC pin is the pulse rising edge
Table 18. Reading mode and start commands
7.5.4.2 Synchronize multi-NAFE with SYNC pulse at SYNC pin
conversion on the rising edge of the SYNC pulse.
7.5.4.3 Synchronize NAFE to host with SYNC pin
synchronization mechanism driven by the host. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.4.4 Synchronize the host to the NAFE through DRDY signal
the correct time. This function is critical for synchronizing the reading time for an infinite reading loop.
7.5.4.5 Synchronize the NAFE and host to the same clock
- Apply an external 18.432 MHz master clock to XI/EXTCLK pin and set SYS_CONFIG0.CK_SRC_SEL[1:0] = 1. This enables coherent measurements and the possibility to synchronize the SPI data fetching using this clock as a timer.
- Use internal 4.608 MHz system clock at GPIO9 pin configuring SYS_CONFIG0.MCLK_OUT_ENABLE = 1 in SYS_CONFIG0 register. This implementation enables synchronization to the NAFE so the host can synchronize the SPI data fetching using this clock as a timer.
7.5.4.6 Reading conversion start - SYNC pulse
SYNC pulse width should be a minimum of two system clock cycles. reading period for the second reading and beyond. SYNC pulse triggers the conversion start for all the reading modes.
1 CMD_SCP
2 Sys_clk
Figure 16. Conversion start
7.5.5 Reading modes
- Single-channel single-reading (SCSR) set by the CMD_SS command
- Single-channel continuous-reading (SCCR) set by the CMD_SC command
- Multichannel single-reading (MCSR) set by the CMD_MS command
- Multichannel multireading (MCMR) set by the CMD_MM command
- Multichannel continuous-reading (MCCR) set by the CMD_MC command
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
The following sections describe the reading modes in details.
7.5.6 Reading sequence
(conversion) process is initiated by either SPI start command or SYNC pulse. Figure 17. Reading modes
- Idle state. Wait for a start event: SPI start command or SYNC pulse
- Update the active channel configuration and pointer location (as needed)
- Wait for the timer of programmable delay to expire
- Start and complete ADC conversion on the selected channel, check active converting channel pointer with
automatically incremented to the next enabled channel after the conversion is complete.
- Loop increment for Continuous-Reading and Multireading modes:
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE b. In Continuous-Reading modes: SCCR, MCCR – ADC jumps to Step 2 and repeats the sequence until interrupted c. In Multireading mode: MCMR – ADC jumps to Step 2 until the reading completion of the last enabled channel defined in CH_CONFIG4.MCH_EN[15:0]. The loop is then broken and ADC returns to Step 1. In Single-Reading mode SS mode, the host issues the conversion start by sending CMD_SS if SYS_CONFIG0.ADC_SYNC = 0, or the SYNC pulse if SYS_CONFIG0.ADC_SYNC = 1. After the NAFE completes the reading conversion process, it returns to idle and waits for the next instruction command or next SYNC pulse. In Continuous-Reading SCCR and MCCR modes, the host issues the conversion start by sending CMD_SC, CMD_MC, or the SYNC pulse (when SYS_CONFIG0.ADC_SYNC = 1 is set). After the NAFE completes first reading conversion process, it jumps to Step 2 and continues the reading process forever or until is interrupted. There are three ways to interrupt an ADC conversion: 1. CMD_END: Stop ADC conversion reading process after the current conversion is completed. 2. CMD_ABORT: Abort the ADC conversion reading process immediately. 3. Conversion start event: a. If SYS_CONFIG0.ADC_SYNC = 0, the last falling edge of SPI command restarts a new conversion. A pulse at the SYNC pin is ignored. b. If SYS_CONFIG0.ADC_SYNC = 1, a rising edge signal at SYNC pin will trigger ADC a new conversion start.
7.5.7 CMD_SS (single-channel single-reading)
Start Single-Channel Single-Reading (conversion) mode. If SYS_CONFIG0.ADC_SYNC = 0, the conversion start is triggered by this SPI command at the last SPI clock falling edge. If SYS_CONFIG0.ADC_SYNC = 1, the conversion start is triggered by SYNC rising edge. In both cases, the conversion is executed on the selected channel. After the conversion is complete, the device returns to its waiting state. Data can be read serially via the MISO pin after the DRDY pin asserts high, or after the reading process is complete. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.5.7.1 Flow chart - SCSR
Figure 18. Flow chart SCSR NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.7.2 Timing diagram - SCSR
- Keep the CSB low after the command was issued. Then wait for DRDY assert high. Data is available at the MISO pin at every rising of SCLK. MSB outputs first.
- Deassert the CSB high, then wait until the DRDY goes high and read the channel data. aaa-046695 ADC data [23:0] CSB SCLK MOSI ID 1 16 1 16 1 24 DRDY
1 CMD_SS
2 T_Sys_clk
Figure 19. CMD_SS timing diagram with CSB high
1 XCMD_SS
Figure 20. CMD_SS timing diagram with CSB low
7.5.7.3 Code example - SCSR
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.5.7.4 Reading period for SCSR
SS Reading period: T_reading = T_fixed + T_prog_delay + T_conv On single reading, T_fixed = (2 × T_sys_clk) ± 1 × T_sys_clk For example, Set CH_DELAY[5:0]=17\\d; #delay 76 sys_clk Set ADC_DATA_RATE[4:0] = 5\\d; #DRO is 12000 sps Set ADC_NORMAL_SETTLING = 0\\d; #Single-cycle mode T_sys_clk =1/sys_clk = 1/4608000 = 0.217 us T_prog_delay = 76 * T_sys_clk #Table Channel Programmable Delay T_conv = 1/12000 = 83.3 us #Table Data Rate Hence,
7.5.8 CMD_SC (single-channel continuous-reading)
Start Single-Channel Continuous-Reading (conversion) mode. If bit SYS_CONFIG0.ADC_SYNC = 0, the conversion start is triggered by this SPI command at the last clock falling edge. If bit SYS_CONFIG0.ADC_SYNC = 1, the conversion start is triggered by SYNC rising edge. In both cases, the conversion is executed on the selected channel until it is interrupted or restarted. The conversion could be interrupted by CMD_ABORT or CMD_END, or could be aborted and restarted by a SYNC pulse if SYS_CONFIG0.ADC_SYNC = 1 or any conversion command if SYS_CONFIG0.ADC_SYNC = 0. Data can be read serially via the MISO pin after the DRDY pin asserts high or after the reading is completed. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.5.8.1 Flow chart - SCCR
Figure 21. Flow chart - SCCR NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.8.2 Timing diagram - SCCR
- Keep the CSB low after the command was issued. Then wait for DRDY pin assert high and read the channel data. Data is available at MISO pin at every rising of SCLK. MSB outputs first.
- De-assert the CSB high, then wait until the DRDY goes high and read the channel data. aaa-046697 * The pulse width of DRDYcan be programmed via DRDY_PWDT bit in SYSTEM_CONFIG0 bit 15. 0: 2 system clocks and 1: 8 systemclocks * Note NAFE reading 1st period is longert +2 sys_clk of the successiveNAFEreading CSB SCLK MOSI ID 1 16 1 24 1 24 1 24 DRDY
1 CMD_SC
Figure 22. CMD_SC timing diagram CSB low/high
7.5.8.3 Code example - SCCR
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.5.8.4 Reading period for SCCR
SC Reading period: T_reading = T_fixed + T_prog_delay + T_conv On first reading, T_fixed = (2 × T_sys_clk) ± 1 × T_sys_clk On subsequent readings, T_fixed = 0. For example, Set CH_DELAY[5:0] = 17\\d; #delay 76 sys_clk Set ADC_DATA_RATE[4:0 ] = 5\\d; #DRO is 12000 sps Set ADC_NORMAL_SETTLING = 0\\d; #Single-cycle mode T_sys_clk =1/sys_clk = 1/4608000 = 0.217 us T_prog_delay = 76 * T_sys_clk #Table Channel Programmable Delay T_conv = 1/12000 = 83.3 us #Table Data Rate Hence, On first reading, T_reading = 0.217 us * ( 2 ± 1 + 76 ) + 83.33 us = 100.3 ± 0.217 us On subsequent readings, T_reading = 0.217 us * ( 0 + 76 ) + 83.33 us = 99.83 us.
7.5.9 CMD_MM (multichannel multireading)
Start Multichannel Multireading (conversion) mode. If SYS_CONFIG0.ADC_SYNC = 0, the conversion start is triggered by this SPI command at the last clock falling edge. If SYS_CONFIG0.ADC_SYNC = 1, the conversion start is triggered by SYNC rising edge. After first conversion, the sequencer will start conversion by sequencing on the enabled channel set via CH_CONFIG4.MCH_EN[15:0] register, from CH0 to CH15. Upon the completion of the last enabled channel, the device returns to waiting state. The conversion could be interrupted by CMD_ABORT or CMD_END, or could be aborted and restarted by SYNC pulse if SYS_CONFIG0.ADC_SYNC = 1 or any conversion command if ADC_SYNC = 0. If an SPI conversion command or a SYNC pulse is issued before completion of the current conversion, ADC aborts the conversion immediately and restarts the conversion starting from first enabled channel. Data can be read serially via the MISO pin after the DRDY pin asserts high or after the reading is completed. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.5.9.1 Flow chart - MCMR
Figure 23. Flow chart MCMR NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.9.2 Timing diagram - MCMR
based on the four configurations stored at these respective locations 0, 4, 8, and 12 in the sequencer table.
1 CMD_MM
Figure 24. Timing diagram - MCMR
7.5.9.3 Code example - MCMR
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.5.9.4 Reading period for MCMR
MM Reading period: T_reading = T_fixed + T_prog_delay + T_conv On first reading, T_fixed = (2 × T_sys_clk) ± 1 × T_sys_clk On subsequent reading, T_fixed = 0 For example, Set CH_DELAY[5:0]=17\\d; #delay 76 sys_clk Set ADC_DATA_RATE[4:0]=5\\d; #DRO is 12000 sps Set ADC_NORMAL_SETTLING=0\\d; #Single-cycle mode T_sys_clk =1/sys_clk = 1/4608000 = 0.217 us T_prog_delay = 76 * T_sys_clk #Table Channel Programmable Delay T_conv = 1/12000 = 83.3 us #Table Data Rate Hence, On first reading, T_reading = 0.217 us * ( 2 ± 1 + 76 ) + 83.33 us = 100.3 ± 0.217 us On subsequent readings, T_reading = 0.217 us * ( 0 + 76 ) + 83.33 us = 99.83 us.
7.5.10 CMD_MC (multichannel continuous-reading)
Start Multichannel Continuous-Reading (conversion) autonomous mode. The CMD_MC is similar to CMD_MM with infinite loop until it is interrupted or restarted. CMD_MC sets multichannel continuous-reading (conversion) mode. If SYS_CONFIG0.ADC_SYNC = 0, the conversion start is triggered by this SPI command at the last clock falling edge. If SYS_CONFIG0.ADC_SYNC = 1, the conversion start is triggered by SYNC rising edge. After first conversion, the sequencer will start conversion by sequencing on the enabled channel set via CH_CONFIG4.MCH_EN[15:0] register, from CH0 to CH15. After the conversion completion of the last enabled channel, the device restarts a new cycle in an infinite loop. The conversion could be interrupted by CMD_ABORT or CMD_END; or could be aborted and restarted by SYNC pulse if SYS_CONFIG0.ADC_SYNC = 1 or any conversion command if SYS_CONFIG0.ADC_SYNC = 0. If an SPI conversion command or a SYNC pulse is issued before completion of the current conversion, ADC aborts the conversion immediately and restarts the conversion, starting from first enabled channel. Data can be read serially via the MISO pin after the DRDY pin asserts high or after the reading is completed. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.5.10.1 Flow chart - MCCR
Figure 25. Flow chart - MCCR NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.10.2 Timing diagram - MCCR
CMD_ABORT or CMD_END is issued. Figure 26. Timing diagram - MCCR
7.5.10.3 Code example - MCCR
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.5.10.4 Reading period for MCCR
MC Reading period: T_reading = T_fixed + T_prog_delay + T_conv On first reading, T_fixed = (2 × T_sys_clk) ± 1 × T_sys_clk On subsequent readings, T_fixed = 0. For example, Set CH_DELAY[5:0] = 17\\d; #delay 76 sys_clk Set ADC_DATA_RATE[4:0] = 5\\d; #DRO is 12000 sps Set ADC_NORMAL_SETTLING = 0\\d; #Single-cycle mode T_sys_clk =1/sys_clk = 1/4608000 = 0.217 us T_prog_delay = 76 * T_sys_clk #Table Channel Programmable Delay T_conv = 1/12000 = 83.3 us #Table Data Rate Hence, On first reading, T_reading = 0.217 us * ( 2 ± 1 + 76 ) + 83.33 us = 100.3 ± 0.217 us On subsequent readings, T_reading = 0.217 us * ( 0 + 76 ) + 83.33 us = 99.83 us.
7.5.11 CMD_MS (multichannel single-reading)
Start Multichannel Single-Reading (conversion) mode. If SYS_CONFIG0.ADC_SYNC = 0, the conversion start is triggered by this SPI command at the last clock falling edge. If SYS_CONFIG0.ADC_SYNC = 1, the conversion start is triggered by SYNC rising edge. Upon completion of each ADC conversion, the logic channel pointer is auto-incremented to the next enabled channel and awaits the arrival of a conversion start trigger. The ADC loops back to the first enabled channel when the last enabled channel is complete. This reading mode could be terminated by issuing the CMD_END or CMD_ABORT. If SYNC pulse or same conversion command is issued before completion of the conversion on the current channel, ADC aborts the conversion immediately and restarts the conversion on the current channel. (This is different from MM and MC modes, which restart on the first enabled channel) Data can be read serially via the MISO pin after the DRDY pin asserts high or after the reading is completed. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
7.5.11.1 Flow chart - MCSR
Figure 27. Flow chart - MCSR NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.5.11.2 Timing diagram - Flow chart - MCSR
Figure 28. Timing diagram - Flow chart - MCSR
7.5.11.3 Code example - Flow chart - MCSR
7.5.11.4 Reading period for MCSR
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.6 ADC code to voltage translation
ADC code output can be translated to voltage with the simple formula provided in Table 19. readout is scaled with a fixed gain of 2.5. 80_0000\\h. The equivalent max- and min-signed decimal are 8,388,607\\d and -8,388,608\\d respectively. temperature translation is provided in Table 19. Table 19. ADC code conversion formulas
7.7 Diagnostic features
made available, as described in the following sections. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
15 OVER_TEMP_ALRM RW 0x0 Overtemperature warning at 145 °C
14 HVDD_ALRM RW 0x0 Enable alarm for HVDD supply detect below preset threshold. 13 HVSS_ALRM RW 0x0 Enable alarm for HVSS supply detect above preset threshold. 12 ADVDD_ALRM RW 0x0 Enable alarm for DVDD supply detect below preset threshold. 10 GPI_POS_ALRM RW 0x0 Enable alarm for rising edge detected at any GPI pins. 9 GPI_NEG_ALRM RW 0x0 Enable alarm for falling edge detected at any GPI pins. 8 CONFIG_ERROR_ALRM RW 0x0 Enable alarm for register configuration error.
7 OVRRNG_ALRM RW 0x0 Enable alarm when one or more data channels is over-range
6 UNDRNG_ALRM RW 0x0 Enable alarm when one or more data channels is under-range.
5 OVRLOAD_ALRM RW 0x0 Enable alarm when one or more data channels is overloaded
4 EXTCLK_FREQ_ALRM RW 0x0 Enable alarm when EXTCLK or XTAL clock period deviates >
20 % from 18.432 MHz INTOSC. threshold is set in THRS_TEMP register bit.
15 OVER_TEMP_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
14 HVDD_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 13 HVSS_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 12 ADVDD_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 10 GPI_POS_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 9 GPI_NEG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 8 CONFIG_ERROR_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 7 OVRRNG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 6 UNDRNG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 5 OVRLOAD_ALRM RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 4 EXTCLK_FREQ_ALRM RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. 0 TEMP_ALRM RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY. Table 20. Alarm and interrupt The alarm clearing behavior is determined by GLOBAL_ALRM_STICKY. See Section 7.9.2 for address, bit order, and description of various global alarm configurations available.
7.7.1 Input under-range and over-range
over-range detection based on its ADC output. be set as INTB pin interrupt with register bit OVRRNG_INT = 1 and UNDRNG_INT = 1, respectively. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.7.2 REFH and REFL for diagnostic
7.7.3 Voltage supply rail monitoring
The NAFE11388 can measure and monitor its own power supplies: HVDD, HVSS, and VDD. When these values are read, a global alarm is issued if the read value is out of the user-programmed threshold. the device to operate above POR level at preset threshold.
7.7.4 Thermal monitoring and thermal shutdown
can provide early over-temperature warning interrupt, TEMP_INT.
7.7.5 Alarm
also be used with configured setting on GPIO_CON, GPI_ENABLE, GPI_EDGE_POS, GPI_EDGE_NEG.
7.7.6 Interrupts
command to global alarm enable register (address = 0x32\\h). specific status byte, by enabling SYS_CONFIG0.STATUS_EN. Each of the status bit is OR’s of all 16 channels. The logic equivalence is shown in Figure 29. Figure 29. Interrupt NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Each individual status bit is concatenated in single byte listed in Table 21. Table 21. Status byte description accordingly. Host can clear this channel-based status by issuing CMD_CLEAR_DATA or CMD_CLEAR_REG. underload/overload, ADC over-range and ADC under-range. already set in the GAI register by writing 1 to the respective bit locations to see the next interrupt event. Note: Writing 1 to the bit that is 0 in GAI register, will not alter it to 1. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 30. Alarm might be toggling, meaning interrupt comes and goes regardless of GAI register read or not.
7.7.8 Configuration or loading error
the configuration error would be set to 1. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
7.8 SPI interface and controls
7.8.1 SPI signal pins
The SPI-compatible serial interface is used to read the conversion data, internal register content and to configure the device and control the ADC. The serial interface consists of four signals: CSB, SCLK, MOSI, and MISO. One external pin, SPI_ADDR, is used as SPI address such that the host can address two devices without using a separate CSB pin. In addition, DRDY and SYNC signals allow the handshaking and data synchronization between the host and the device. The conversion data are provided with an optional CRC code for improved data integrity. 24-bit ADC word can be read with and without 8-bit CRC appended at the end of data. The SPI pin functions are described in the following sub-sections.
7.8.1.1 CSB (active low)
CSB is an input pin that enables the communication between the host and the chip. CSB must remain low for the entire data transaction. When CSB is set to high, the serial interface is reset, SCLK input and command inputs are ignored.
7.8.1.2 SCLK
SCLK is the serial interface clock that operates up to 32 MHz. It is a noise-filtered, Schmitt-triggered input used to clock data in and out of the chip. Serial input data is latched in the falling edge of SCLK and serial data outputs from the chip are updated on the rising edge of SCLK.
7.8.1.3 MOSI
MOSI is the serial data input to the chip. MOSI is used to input commands and register data to the chip.
7.8.1.4 MISO
MISO is the serial data output from the chip. MISO data contains: internal registers data, ADC results, status byte, and/or 8-bit CRC if CRC_EN and/or STATUS_EN are set to 1, respectively. When CSB is high, MISO is in high-impedance. When CSB is low, MISO is updated on the rising edge of the SCLK.
7.8.1.5 SPI_ADDR
SPI_ADDR is an additional input pin used to address a second device with a single CSB to reduce the number of chip select signals required.
7.8.1.6 DRDY
DRDY (rising edge) is an output pin that indicates the conversion status. DRDY is driven to high when the new conversion result is stored in the SPI buffer and ready for reading. DRDY pulse stays high for 2 x T_sys_clk if SYS_CONFIG0.DRDY_PWDT bit = 0. Otherwise, the pulse stays high for 8 x T_sys_clk if DRDY_PWDT bit = 1.
7.8.1.7 SYNC
SYNC is an external pin used to synchronize the data conversion to external events. The user can start any conversion mode either by using SPI command or asserting low to high transition on the SYNC pin given that the SYS_CONFIG0.ADC_SYNC bit = 1. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
The minimum width of SYNC pulse should be 2 x T_sys_clk.
7.8.1.8 INTB (active low)
programmed as open-drain with internal pullup or CMOS output.
7.8.2 SPI communication protocols
set to 0 for write, whereas it should be 1 for read. Figure 31. SPI write timing Figure 32. SPI read timing
7.8.2.1 Write without CRC
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 33. Write without CRC
7.8.2.2 Read without CRC
used to read back the internal register contents of the chip and the ADC conversion results. Figure 34. Read without CRC
7.8.2.3 CRC-8 generator
default off, CRC_EN = 0. Setting CRC_EN = 1 will enable CRC feature. y = x8 + x2 + x + 1 equivalent to binary number is 100000111. three bytes depending on the data transfer operation. When CRC is enabled, the CRC byte is appended after the 16-bit command (two bytes) and after the ADC data. ignored and a CRC error is generated. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
The CRC_ERROR flag is routed out to GPIO2 if SYS_CONFIG0.CRC_ERROR_ON_GPIO2 is set to 1. SYS_STATUS0.CRC_ERROR bit is cleared upon reading.
7.8.2.5 Write with CRC
Figure 35 and Figure 36 show the host writes NAFE 16-bit and 24-bit internal register respectively.
- For 16-bit register write: The host first calculates the 8-bit CRC_A on 16-bit address and appends the 8- bit CRC_A after the address. The host then calculates the 8-bit CRC_D on 16-bit data and appends the 8-bit CRC_D after 16-bit data.
- For 24-bit register write: The host first calculates the 8-bit CRC_A on 16-bit address and appends the 8- bit CRC_A after the address The host then calculates the 8-bit CRC_D on 24-bit data and appends the 8-bit CRC_D after 24-bit data. In both cases, the host should send an extra 8-bit clock to receive back the calculated CRC_D from the device. The 16-bit address register includes device ID bit, RW_L bit, RA bits, and don’t care bit (0). CSB SCLK MOSI MISO aaa-046711 ID 1 16 17 24 25 40 41 48 49 56
0 X CRC-2 CRC-2 (WDATA) 0X0WDATA[15:0]
*CRC-2 = 2 byte is calculated by Host to produce CRC-2. Figure 35. Host writes to register 16-bit with CRC enabled
0 X CRC-2 CRC-3 (WDATA) 0X0WDATA[23:0]
*CRC-2 = 2 byte is calculated by Host to produce CRC-2. Figure 36. Host writes to register 24-bit with CRC enabled
7.8.2.6 Read with CRC
shows host read data from the 16-bit register. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
1 X CRC-2
Figure 37. Host read data from the 24-bit register
7.8.2.7 System configuration with CRC
Two-byte command: Two-byte command format with no data return. shows the timing of two-byte command with non-return ADC data.
- Command examples: CMD_CH0, … CMD_CH15, CMD_ABORT, CMD_END, CMD_CLEAR_ALARM, CMD_CLEAR_DATA, CMD_RESET, CMD_REOAD The host calculates the CRC of the two-input command bytes. Device CRC-2 byte is calculated by device, output based on the two received command bytes. If the two CRC values match, the command is executed at the beginning of the last falling edge of SCLK of the fourth byte in the sequence. Asserting CSB high before the command completes will result in command termination. When a new command starts, the device must see the CSB transition from high to low. If both CRC_EN, and STATUS byte output format are enabled, then the CRC calculation includes status byte plus the ADC conversion data, CRC4 for 24-bit ADC and CRC3 for 16-bit ADC. CSB aaa-046714 *CRC-2 = 2 byte is calculated by Host to produce CRC-2. The two byte (16 bits) includes ID, RW, Command and X bit SCLK Device CRC-2Z Status[7:0] ADCn[23:0] ADCn+1[23:0]CRC4 *CRC-4 = 4 byte is calculated by Device on the Status[7:0] + ADC[23:0] to produce CRC-4 CRC-4Status[7:0] MOSI MISO ID RW_L X CRC-2 00hCommand 16 17 24 25 32 40 64 65 73 81 82 105 1124133 DRDY CMD_SS ends at this clock edge
Figure 38. Conversion command data read operation 2/24-bit ADC, CRC_Enable = 1, Status_Enable = 0 Figure 39. Regular read 24-bit data with CRC_EN = 1 NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
CRC-2 means 2 byte is calculated by Host to produce CRC-2. Figure 40. Two-byte command format with return data Two-byte command: Two-byte command format with data return. timing of two-byte command with ADC data return.
- Command examples: CMD_SS, CMD_SC, CMD_MM, CMD_MC, and CMD_BURST_DATA The host calculates CRC of the two-input bytes and sends the CRC-2 after the 16-bit command. Device CRC-2 byte is calculated by device, output based on the two received command bytes. If the two CRC values match, the command is executed. After the host sends CRC byte, it can continue to send eight more clocks to get the device calculated CRC before DRDY goes high. The host can keep the CSB low, while waiting for DRDY to assert HI, then provide the number of clocks required to retrieve the ADC conversion data along with its respective calculated CRC. If the device is 24-bit ADC, then CRC calculation will be based on three ADC bytes. If the device is 16-bit ADC, then CRC calculation will be based on two ADC bytes. CSB DRDY SCLK MOSI MISO aaa-046717 ID 1 16 17 24 25 32 00h 33 56 57 64 65 97 9889 CMD_SS ends at this clock edge 128121 RW_L X CRC-2 Device CRC-2 ADCn [23:0] ADCn+1 [23:0] ADCn+2 [23:0] *CRC-2 = 2 byte is calculated by Host to produce CRC-2. The two byte (16 bits) includes ID, RW, Command, and X bit *CRC-3 = 3 byte is calculated by Device on the ADC[23:0] to produce CRC-3 CRC-3CRC-3 CRC-3Z Command
Figure 41. Conversion command data read operation 2/24-bit ADC, CRC_ENABLE = 1, Status_Enable = 0
7.8.3 SPI programming and commands
and RA5 bit is always set to 1 when accessing the registers.
7.8.3.1 Commands definition
16-bit SPI instructions and mnemonic.
7.8.3.1.1 CMD channel selection
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 22. CMD channel selection
7.8.3.1.2 CMD initialize/clear
CMD_CLEAR_ALARM, CMD_CLEAR_DATA, CMD_CLEAR_REG, CMD_RELOAD, and CMD_RESET.
- Chip power-on reset (POR)
- RSTB accessible by pulling the pin to ground
- CMD_RESET Hardware reset is achieved by pulling pin RSTB = 0 V or POR. When in reset, all HV input pins and GPIO pins are in high-Z input mode, internal voltage reference is used, ADC digital filters are cleared, all user registers are set to their default values and all NVM shadow register content will be reloaded. The input clock source will be defaulted back to internal RC oscillator and go through autoclock switching within 50 ms if the external clock is applied or crystal is installed. CMD_RESET is the same as the hardware reset by pulling RSTB pin down to GND. Issuing the CMD_CLEAR_ALARM command clears GLOBAL ALARM INTERRUPT bits at register address: 0x33\\h. Issuing the CMD_CLEAR_DATA command will clear all channel data (CH_DATA0 – CH_DATA15) registers to 0x000000. Issuing the CMD_CLEAR_REG command clears the user registers, except the clock source select, SYS_CONFIG0.CK_SRC_SEL [1:0]. The clock source select bit does not get cleared even if they are part of the user’s registers. The user can change this register after POR, while any conversion is in active. For instance, if CK_SRC_SEL held a value other than 0 before the command was issued, it would stay the same after this command was issued. Note: CRC_EN is also cleared. Issuing the CMD_RELOAD command reloads NVM contents to shadow registers. NVM contents consist of the NAFE trims parameters and offset and gain calibration coefficients. This command does not reset user registers. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
Table 23. CMD initialize/clear
7.8.3.1.3 CMD reading modes
Table 24. CMD reading modes
7.8.3.1.4 CMD burst data
Table 25. CMD burst data (determined by MCH_EN[15:0] bits). NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Note: If MCH_EN = 0x8000, data in CH_DATA15 is read. Figure 42. Burst data command NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
7.8.3.1.5 CMD CRC
Table 26. CMD CRC CMD_CALC_CRC_CONFG: Calculate CRC sum for all 16-bit user configuration registers and save result to 0x25\\h(CRC_CONFIG_REGS). CMD_CALC_CRC_COEF: Calculate CRC sum for all 24-bit CAL coefficient and threshold registers and save result to 0x26\\h(CRC_COEF_REGS). CMD_CALC_CRC_FAC: Calculate all factory OTP trim registers and save result to 0x27\\h(CRC_TRIM_INT[15:0]). register address at 0x25, 0x26, or 0x27 if CMD_CALC_CRC_CONFG, CMD_CALC_CRC_COEF, or CMD_CALC_CRC_FAC is used respectively.
7.8.3.1.6 Read/Write
1 RA12 RA11 RA10 RA9 RA8 RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 eg: Read register CH_CONFIG0 :
0 RA12 RA11 RA10 RA9 RA8 RA7 RA6 RA5 RA4 RA3 RA2 RA1 RA0 eg: Write register CH_CONFIG0 :
Table 27. Read/Write
7.8.3.2 Channel data readback
- Directly after conversion, read data is stored to the channel data register indicated by the rising edge of DRDY. The conversion result is automatically
transferred to the SPI data buffer while the host provides the SPI clock. However, the CSB needs to stay low after the start conversion event has been issued.
- Read data from the channel data register. This requires a new SPI transaction that addresses and fetches the channel data register.
7.9 Register map
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
- 16-bit configuration and status registers
- 24-bit coefficient registers
- 24-bit or 16-bit data registers for 24-bit or 16-bit options 7.9.1 16-bit channel-based configuration CH_CONFIG0..2[15:0] are channel-based registers. Before reading or writing to CH_CONFIG registers of a channel, select the channel by issuing CMD_CHi to set Register(16-bit) Bit order Bit name RW Reset Short description 15:12 HV_AIP[3:0] RW 0x0 HV Positive input pin select: 0\\h = internal GND, 1\\h = AI1P, 2\\h = AI2P, 3\\h = AI3P, 4\\h = AI4P, 5\\h = REFH, 6\\h = REFL, 7\\h = AICOM, 8\\h = not used, 9\\h to F\\h = not used. 11:8 HV_AIN[3:0] RW 0x0 HV Negative input pin select: 0\\h = internal GND, 1\\h = AI1N, 2\\h = AI2N, 3\\h = AI3N, 4\\h = AI4N, 5\\h = REFH, 6\\h = REFL, 7\\h = AICOM, 8\\h = not used, 9\\h to F\\h = not used. 7:5 CH_GAIN[2:0] RW 0x0 Select the channel gain (V/V): 0\\h = 0.2x, 1\\h = 0.4x, 2\\h = 0.8x, 3\\h-7\\h = unused. 4 HV_SEL RW 0x0 Select HV or LV signals for ADC conversion: 0 = LVSIG_IN, 1\\h = HV_AIP-HV_AIN signals. 3:1 LVSIG_IN[2:0] RW 0x0 LV signals (pos, neg) select: 0\\h = (REF/2,REF/2), 1\\h = (GPIO0,GPIO1), 2\\h = (REF_Coarse,REF/2), 3\\h = (VADD,REF/2), 4\\h = (VHDD,REF/2), 5\\h = (REF/2,VHSS), CH_CONFIG0 0x20\\h
0 TCC_OFF RW 0x0 Proprietary Channel Temperature Coefficient Correction: 0\\h = TCC ON, 1\\h = TCC OFF
Coefficient Registers. See Table 14 . 11:8 CH_THRS[3:0] RW 0x0 Channel Over- and under-range threshold: See Table 29. previous conversion, 1\\h = reset digital filters. 15:0 MCH_EN[15:0] RW 0x0000 Enable logical configurable channel for ADC conversion in Sequencer mode: 0 = disable, 1 = enable. Table 28. 16-bit channel-based configuration NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
- Output data: DATA0..15
- Over-range alarm threshold: OVR_THRS0..15
- Under-range alarm threshold: UDR_THRS0..15
- Factory or user-calibration gain coefficients: GCC0..15
- Factory or user-calibration offset coefficients: OCC0..15 The non-channel based registers OPTC0..15 are optional coefficients used for storing factory calibrated parameters. Register (24-bit) Bit order Bit name RW Reset Short description CH_DATA0..15 0x40\\h - 0x4F\\h 23:0 DATA0[23:0] .. DATA15[23:0] R 0x00_0000 Channel output data. Each channel has a corresponding data register. DATA0[23:0] is converted output of CH0.. DATA15[23:0] is converted output of CH15. CH_CONFIG5 0x50\\h - 0x5F\\h 23:0 OVR_THRS0[23:0] .. OVR_THRS15[23:0] RW 0x00_0000 Over-range threshold setting for each logical data channel. CH_CONFIG6 0x60\\h 0x6F\\h 23:0 UDR_THRS0[23:0] .. UDR_THRS15[23:0] RW 0x00_0000 Under-range threshold setting for each logical data channel. GAIN_COEF0..15 0x80\\h-0x8F\\h 23:0 GCC[23:0] RW 0x Calibrated gain coefficients. The user may alter or update the values to fit their application. For each of the logical channel setup, these GAIN_COEF registers are indexed addressable by pointer set by register bits CH_CAL_GAIN_OFFSET[4:0]. Initially after CHIP_READY, the content of these registers are populated with factory-calibrated coefficients, refer to TABLE_FAC_COEF if applicable. Note: Whenever the chip is in RESET, the factory-calibrated coefficient is reloaded from OTP into the registers. These same registers are used for displaying the factory calibrated coefficient upon RESET in certain order. However, the user has full read/write access and may reshuffle the order and coefficient values according to user-configured channels. OFFSET_COEF0..15 0x90\\h-0x9F\\h 23:0 OCC[23:0] RW 0x Calibrated offset coefficients. The user may alter or update the values to fit their application. For each of the logical channel setup, these OFFSET_COEFF registers are indexed addressable by pointer set by register bits CH_CAL_GAIN_OFFSET[4:0]. Initially after CHIP_READY, the content of these registers are populated with factory-calibrated coefficients, refer to TABLE_FAC_COEF if applicable. Note: Whenever the chip is in RESETx, the factory-calibrated coefficient is reloaded into the registers from OTP. These same registers are used for displaying the factory-calibrated coefficient upon RESETx in certain order. However, the user has full read/write access and may reshuffle the order and values, then update CH_CAL_GAIN_OFFSET accordingly. OPT_COEF0..13 0xA0\\h-0xAD\\h 23:0 OPTC[23:0] RW 0x00_0000 Extra register for temporary storing coefficients, eg it can be used as Self-calibrated ADC values with internal VREF and REFH, REFL at CH_GAIN or Calibrated values with Excitation sources. See Table 13.
Table 29. 24-bit channel-based coefficient and data registers
7.9.3 System-level configurations and status registers
0x25\\h 15:0 CRC_CONF_REGS[15:0] R 0x0000 Integrated CRC result of all Configuration registers. CRC_COEF_REGS 15:0 CRC_COEF_REGS[15:0] R 0x0000 Integrated CRC result of all user's coefficient registers. Table 30. System-level configurations and status registers NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
0x27\\h 15:0 CRC_TRIM_REGS[15:0] R 0x0000 Integrated CRC result of all factory trim OTP registers. 0x35\\h 15:0 CH_OVR[15:0] R 0x0000 Channel over-range, logical CH15 is bit 15, CH0 is bit 0. 0x36\\h 15:0 CH_UDR[15:0] R 0x0000 Channel under-range, logical CH15 is bit 15, CH0 is bit 0.
15 DRDY_PWDT RW 0x0 DRDY pulse width duration (# of SYSCLK cycle): 0\\h = 2, 1\\h = 8
14 ADC_DATA_OUT_16BIT RW 0x0 ADC data register readout: 0\\h = 24 bit, 1\\h = 16 bit
12 MCLK_OUT_ENABLE RW 0x0 Enable the master clock(2*SYSCLK) output to GPIO9 pin. This bit supersedes and ignores the other GPIO9 setting. 0\\h = Both REF_BYP and REF_ADC use REF_INT. 1\\h = REF_BYP uses REF_INT and REF_ADC uses REF_EXT. 2\\h = REF_BYP uses REF_EXT and REF_ADC uses REF_INT. 3\\h = REF_BYP uses REF_EXT and REF_ADC uses REF_EXT. Note: Internal reference is always powered on. 7 CRC_EN RW 0x0 Enable CRC: 0\\h = disable, 1\\h = enable. Table 30. System-level configurations and status registers...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
5 ADC_SYNC RW 0x0 ADC Synchronization mode enabled for host-driven with SYNC pulse at pin. This works with all conversion modes. specific bit in the Global Alarm interrupt register. 2 SPI_DOUT_DRIVE RW 0x0 Increase DOUT output drive if high capacitance loading. 1 INTB_DRIVER_TYPE RW 0x0 INTB pin driver type: 0 = 100 Kohm pullup with open drain, 1 = CMOS push-pull. 15 SINGLE_CH_ACTIVE R 0x0 Single-channel conversion mode indicator, which includes CH_DELAY. 0\\h = idle, 1\\h = active. 14 MULTI_CH_ACTIVE R 0x0 Multichannel Conversion mode indicator, which includes CH_DELAY. 0\\h = idle, 1\\h = active.
12 CRC_ERROR R 0x0 CRC error encountered
7:4 ADC_CONV_CH[3:0] R 0x0 The current active logical channel. 15 OVER_TEMP_ALRM RW 0x0 Overtemperature warning at 145 ℃. 14 HVDD_ALRM RW 0x0 Enable alarm for HVDD supply detect below preset threshold. 13 HVSS_ALRM RW 0x0 Enable alarm for HVSS supply detect below preset threshold. 12 ADVDD_ALRM RW 0x0 Enable alarm for DVDD supply detect below preset threshold. 10 GPI_POS_ALRM RW 0x0 Enable alarm for rising edge detected at any of GPI pins. 9 GPI_NEG_ALRM RW 0x0 Enable alarm for falling edge detected at any of GPI pins. 8 CONFIG_ERROR_ALRM RW 0x0 Enable alarm for register configuration error. 7 OVRRNG_ALRM RW 0x0 Enable alarm for one or more data channel is over-range. 6 UNDRNG_ALRM RW 0x0 Enable alarm for one or more data channel is under-range. 5 OVRLOAD_ALRM RW 0x0 Enable alarm for one or more data channels is over-loaded or under-loaded. 4 EXTCLK_FREQ_ALRM RW 0x0 Enable alarm when XTAL or EXTCLK frequency varies with internal CLK by XX. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
0 TEMP_ALRM RW 0x0 Enable programmable temperature alarm; the triggering threshold is set in THRS_TEMP register bits.
14 HVDD_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
13 HVSS_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
12 ADVDD_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
10 GPI_POS_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
9 GPI_NEG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
8 CONFIG_ERROR_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
7 OVRRNG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
6 UNDRNG_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
5 OVRLOAD_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
4 EXTCLK_FREQ_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
0 TEMP_INT RW 0x0 Bit clear behavior controlled by GLOBAL_ALRM_STICKY
15:0 THRS_TEMP[15:0] RW 0x0000 Temperature threshold in 2's complement for setting custom temperature alarm. 0x7F\\h 15:0 CRC_TRIM_INT[15:0] R 0x CRC sum of internal trims, to be used for comparison against CRC_TRIM_REGS[15:0]. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
8 Limiting values
8.1 Maximum rating
or permanent damage to the device. Table 31. Absolute maximum rating [1] [1] These are stress ratings at room temperature only. Functional operation of the product with conditions at or above its maximum ratings is not implied. Device reliability may be affected if stressed at or beyond limits for extended periods. [2] Supply pins HVDD-AGND and AGND-HVSS are dc-clamped to 29 V. with 2.5 kΩ external series resistor for duration of up to one hour. [4] Output pins REFH, REFL are diode-clamped to REF_BYP and AGND internally. voltage at pin is 0.3 V (a) above AVDD/DVDD or (b) below AGND/DGND. [6] Digital output pins, current limit is ±10 mA. recommended. Any other loading will affect the device functionality adversely. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
8.2 ESD stress rating and latch-up
Table 32. ESD stress rating and latch-up NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
9 Thermal characteristics
Table 33. Thermal characteristics or permanent damage to the device. the package bottom side dead center. application-specific environment. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
unless otherwise stated. The minimum and maximum specifications cover TA = -40 ⁰C to +125 ⁰C. V, respectively. GEv is gain error expressed in [V] as GE*FS. Table 34. HV input ranges Calibrated offset error without factory CAL coefficients. Calibrated gain error without factory CAL coefficients. Table 35. 24-bit HV input accuracy without factory calibration NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 36. 24-bit HV input initial accuracy with calibration and additional errors could arise from other test setup and conditions. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Single-ended inputs. Internal reference, TA = -25 °C to +105°C. Single-ended inputs. Internal reference, TA = -40 °C to +125°C. internal reference and G = 0.2 V/V, CH_CHOP = 1, TCC_OFF = 1. internal reference and G = 0.8 V/V, CH_CHOP = 1, TCC_OFF = 1. Table 37. 24-bit HV input temperature and aging drift characteristics [1] Data is based on standard high-temperature operating life (HTOL) method. Initial accuracy without factory CAL coefficients. Single-ended inputs. Initial accuracy without factory CAL coefficients. Single-ended inputs. Initial accuracy without factory CAL coefficients. Single-ended inputs. E_VHi REFH error Initial accuracy without factory CAL coefficients, REFH to AGND. Table 38. 16-bit HV input accuracy without factory calibration NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 39. 16-bit HV input accuracy with calibration and additional errors could arise from other test setup and conditions. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Single-ended inputs. Internal voltage reference, TA = -25 °C to +105 °C. Single-ended inputs. Internal voltage reference, TA = -40 °C to +125 °C. Table 40. 16-bit HV input temperature and aging drift coefficients [1] Data is based on standard high-temperature operating life (HTOL) method. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 41. HV input channel characteristics NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Power supplies accuracy HVDD, HVSS and DVDD through ADC readback. Table 42. LV MUX inputs/GPIO0-GPIO1 as analog input Table 43. Temperature sensor Table 44. Internal voltage reference (VREF) [1] An initial accuracy error could be affected by mechanical stress post assembly. [2] Data is based on standard high-temperature operating life (HTOL) method. Table 45. Clock oscillators NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Table 46. Power supplies [1] Not production tested and only limited samples were verified at ± 28 V supplies. Table 47. GPIO and digital I/O pins Table 48. SPI timing and characteristics NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 43. SPI timing parameters NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
11.1 Typical application block diagram
64 AGND
61 GPIO2
60 GPIO3
59 GPIO4
56 GPIO5
55 GPIO6
54 GPIO7
53 GPIO8
52 GPIO9
63 GPIO0
62 GPIO1
51 DGND
58 DGND
57 DVDD
50 EXTCLK/XI
48 LDO_DIG
18.432 MHz
47 DGND
46 DVDD
38 DGND
37 SPI_ADDR
40 SYNC
45 DRDY
44 MISO
43 MOSI
36 RSTB
35 AVDD
33 AGND
34 AGND
42 SCLK
39 INTB
Figure 44. Typical application block diagram Note: Dash boxes on AI1N, AI2P, AI2N inputs represent the dashed circuitry on AI1P. pins. For additional surge protection, TVS diodes could be added preceding the 2.5 kΩ series resistor.
11.2 Design for EMC
NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE and IEC61000-4-4 electrical fast transient and burst immunity up to ±4 kV on AI1P..AI4P, AI1N..AI4N, AICOM pins with 2.5 kΩ to 5.0 kΩ series MELF-type resistor without the need of external TVS on evaluation boards, while protection diodes are necessary at HVDD and HVSS pins. Besides HV input and supply pins, the rest of the LV pins are also tested for ESD to the same maximum rating, as shown in Table 31. In applications where the surge protections are needed on LV pins, an external TVS suppressor will be needed.
11.3 Programmable logic controller I/O module
11.3.1 Design example: ±10 V input module
AI3P, AI3N, AI4P and AI4N in Figure 44 illustrates an example of a ±10 V analog input channels for programmable logic controller (PLC). These HV inputs can be protected by current limiting with the series resistor along with its internal clamping diodes to HVDD and HVSS supplies. The signal from the transmitter is filtered by the external RC filter to remove EMI and RFI interference when operated in noisy environments. The negative input signal is connected to AICOM at 0 V. The ADC measures the differential voltage between inputs AI1P and AICOM. The input configuration is single-ended with the input voltage driven ±10 V relative to AICOM at 0V. The internal oscillator is selected and EXTCLK/XI pin is shorted to DGND. The serial interface and digital control lines of the ADC are connected to the host. Two Zener diodes are installed to clamp the high-voltage supply (HVDD-AGND and AGND-HVSS) to provide overvoltage protection if an input signal is present with module power off.
11.3.2 Design requirements
The ADC programmability allows various tradeoffs of sample rate, conversion noise, and conversion latency.
11.3.2.1 Design goal values
- Accuracy: ±0.05 %
- Temperature range (internal module): -25 °C to +105 °C
- Acquisition period: 50 μs
- Effective resolution: 19 bits
11.3.2.2 Design parameter value
- Nominal signal range: ±10 V
- Extended range: ±12 V
- Input impedance: 1000 MΩ
- Overvoltage rating: ±40 V
11.3.2.3 Detailed design procedure
A key consideration in the design of an analog input module is the error over the ambient temperature range resulting from the drift of gain, offset, reference voltage, and linearity error. This includes the initial offset and gain (including reference voltage error) after factory calibration. Figure 45 shows the maximum drift error of the NAFE over the -25 °C to +105 °C temperature range. The maximum error drift is < 0.02 % in the temperature range of -10 °C to 90 °C and 0.04 % in the temperature range -25 °C to 105 °C. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
Figure 45. Temperature drift test resolution calculates to 19.5 bits, which meets the design requirement. Figure 46. ADC conversion results
11.4 Power supplies and component selection
11.4.1 HV input pin protection and HV supply clamp
current. It is recommended to add supply clamping with Zener diodes at HVDD and HVSS to improve reliability. In case of surge events, TVS diodes could be added at the source side, before the resistor. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
11.4.2 Power supply sequencing
As with many multiple-power supply systems, proper sequencing of the different supplies during power up and power down is a common practice to ensure robust device biasing without unnecessary electrical overstress. Though NAFE11388 devices were tested for robustness under various power supply ramping rates and order of sequences, testing is insufficient to cover all applications. Thus, for NAFE11388 devices, it is recommended to ramp up AVDD, DVDD before HVDD and/or HVSS. Ramping down HVDD and/or HVSS to ~3 V or less before starting to ramp down AVDD and DVDD, is also recommended. In most cases, any ramp rate slower than ±10 V/µs on HVDD, HVSS is acceptable.
11.4.3 HV input pin resistor
An external 2.5 kΩ series resistor is required at each of the AIxP, AIxN and AICOM pins. Higher resistance can lower the current limit in case of fault conditions with the expense of higher voltage error due to pin or board leakages and mismatches. Lower resistance is generally not advised in view of system reliability against surge and ESD events. For precision HV applications, high-pulse load MELF resistors are typically used and often with TC > 100 ppm/ ⁰C. With low input leakage current and the differential input architecture in the NAFE11388, the requirement on the temperature coefficient of the resistor is largely relaxed. If 1 % resistance tolerance is used, it meets the accuracy requirement in most applications. Note: For precise, high common-mode rejection single-ended measurement, AICOM pin in series with the same resistor type and value is to be used, instead of internal GND.
11.4.4 Crystal
The NAFE11388 offers multiple 18.432 MHz clock-source options:
- Internal oscillator
- Crystal oscillator
- External clock source/module For robustness, a crystal with higher drive level >100 µW is recommended.
11.4.5 Capacitors
Use of high-grade capacitors is recommended for the following pins: REFP_ADC/REFN_ADC (1 μF, X7R) and CAPP/CAPN (1 nF, C0G).
11.4.6 Grounds and plane
Good layout practices are crucial to realize the full performance of the ADC. For best performance, dedicate an entire PCB layer to a ground plane. Do not route any other signal traces on this layer.
11.5 System-level calibration
11.5.1 Procedures for gain and offset calibrations
This section describes the steps in performing digital calibration for offset and gain error correction. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
11.5.1.1 Transfer characteristics
The NAFE11388 integrates an offset and gain correction circuitry. The offset correction (Oc) precedes the gain correction (Gc) in digital domain. The ideal transfer characteristic is The actual transfer characteristic is Where Ga and Oa are the actual gain and actual offset respectively. The calibrated transfer characteristic is Where Gc and Oc are the correction gain and offset coefficients, respectively.
11.5.1.2 Voltage and current input gain and offset calibration procedures
This section describes the steps for performing offset and gain digital calibration for voltage or current input.
11.5.1.2.1 Steps for gain CAL
- Set 2. Set 3. Put a voltage source equals to x1, about +100 % of full-scale. 4. Read 5. Put a voltage source equals to x2, about -100 % of full-scale. 6. Read 7. Calculate 8. Set
11.5.1.2.2 Steps for offset CAL
- Plug 2. Calculate 3. Set
11.5.2 Factory calibration and self-calibration
The NAFE11388 offers different calibration features to improve system accuracy at lower cost. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE The NXP factory-calibrated devices increase initial system accuracy while reducing the capital expenditure for expensive test instruments and reducing the production test time. The NAFE11388 stores factory-calibrated coefficients based on two points self-calibration to reduce the gain and offset error. The NAFE11388 includes two voltage sources to perform built-in or dynamic end-to-end self-calibrations. The ratiometric REFH and REFL voltage sources derived from the REF_BYP in combination with 0 V source (GND- GND) provide a precise and calibrated source for gain and offset calibration of all signal paths except reference voltage. The two points gain and offset calibration is performed measuring REFH-GND (or REFL-GND) and GND-GND and comparing against the internal stored value REFH-GND (or REFL-GND) and GND-GND = 0 V to calculate the gain and offset coefficients. Typically, REFH-GND with a typical value of 2.3 V, is suggested for low-channel gain, while RFEL-GND, with a typical value of 0.2 V, is suggested for high-channel gain. For systems that require low offset, an offset calibration could be performed measuring AICOM-AICOM to calculate and calibrate the offset error. Alternately, the NAFE11388 offers an automatic offset reduction circuit that is enabled by setting, CH_CONFIG1.CH_CHOP = 1, to activate the Precision mode. In this mode, the ADC runs two conversions and takes the average of the difference for offset removal. Note: The output data rate is halved. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE
12 Typical operating characteristics
VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. Typical operating characteristics NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. 048756 Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. TUE over temperature over temperature Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, internal 2.5 V reference, TA = 40 ⁰C, unless otherwise specified. Typical operating characteristics...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
Figure 47. Package outline HVQFN64 (SOT804-3(D) ) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 48. Package outline detail HVQFN64 (SOT804-3(D) ) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 49. Reflow soldering footprint part 1 for HVQFN64 (SOT804-3(D) ) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
Figure 50. Reflow soldering footprint part 2 for HVQFN64 (SOT804-3(D)) NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
- Table 2: Added "NAFE11148B40BS"
- Table 3: Added "NAFE11148B40BS" copyright
- Table 38: Symbols "OEi", "GEi" and "INL" removed Conditions, Typ, and Max values for "G = 16 V/V" and "G = 1 V/V"
- Table 39 – Symbol "OE": Removed Conditions, Typ, and Max values for "G = 16 V/V" and "G = 1 V/V", changed "G = 0.8 V/V" Max value from "±191" to "±382" and "G = 0.2 V/V" Max value from – Symbol "GE": Removed Conditions "Initial gain error with factory calibration, G = 16 V/V, TA = +40 °C" and "Initial error with factory calibration, G = 1 V/V, TA = +40 °C" and associated Typ and Max values – Symbol "INL": Removed Conditions, Typ, and Max values for "G = 16 V/V" and "G = 1 V/V"
- Updated appearance of Section 14
- Updated Legal information NAFE11388 v.3 30 October 2023 • Updated Keywords on Page 1: Added "NAFE11348" part number and "16-bit"
- Updated Table 1: Added row for "NAFE11348B40BS"
- Updated Table 2: Added three rows for "NAFE11348B40BS" part number
- Updated Table 3: Added row for "NAFE11348B40BS" part number
- Updated Table 30: Changed "Short description" of "SYS_ CONFIG0 0x30\\h" "Bit Name" "3" from "... 1\\h = Write 0 to clear a specific bit." to "... 1\\h = Write 1 to clear a specific bit in the Global Alarm interrupt register."
- Updated Table 35 title
- Updated Table 36 title
- Updated Table 37 title
- Added Table 38; Table 39; Table 40 NAFE11388 v.2 21 March 2023 • Updated appearance of Revision history
- Section 2: Changed "Robust 8 kV HBM ESD and IEC61000- 4-5 2 kV surge protection" to "Robust 7.5 kV HBM ESD and IEC61000-4-5 2 kV surge protection"
- Table 36 – Changed table title. – Under "Conditions" column: changed "Total" to "Initial" - four occurrences; changed "Calibrated" to "Initial" - one occurrence; changed "Gain" to "Initial Gain" - three occurrences. – Added rows to "Symbol" GE: "Initial Gain Error with Factory calibration, G = 16 V/V, TA = +40 °C" and "Initial Gain
Table 49. Revision history NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
- Table 41: – Changed "Symbol" CMR50/60 Conditions from "Shorted differential inputs pair. VCM = -1 V to +1 V 50Hz/60Hz. DRO = 10 sps, SINC4 filter" to "Shorted differential inputs pair. VCM = ±VFS, 50Hz/60Hz. DRO = 10 sps, SINC4 filter".
- Table 48: Changed text above Table 44 from "VHVDD = - VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, typical values are at TA = 25 ⁰C …" to "VHVDD = -VHVSS = 15 V, VAVDD = VDVDD = 3.3 V, typical values are at TA = 40 ⁰C …".
- Section 7.3.4: Updated text, added Table 6.
- Table 32 – Updated Description from "Latch-up at 125 ⁰C" to "Latch-up at 150 ⁰C". – Updated all Max values from "8000", "1000", and "250" to "7500", "750", and "200", respectively.
- Section 7.3.6.1: Updated "AFEOUT" equation to "(ADCOUT - CAL_OFFSET)".
- Section 11.5.1.2.1: Updated appearance of "y1 = " and "y2 = " equations.
- Updated Figure 44.
- Section 12: Rearranged order of figures
- Added paragraph after Figure 44.
- Section 12: Reordered figures. Updated "Hysteresis PGA = 0.2 V/V", "Hysteresis PGA = 0.8 V/V", "Offset overtemperature PGA = 0.2 V/V", and "Offset overtemperature PGA = 0.8 V/V" figures.
- Section 11.2": Changed end of first paragraph from " … with 2.5 kΩ series MELF-type resistor without the need of external TVS on evaluation boards, while protection diodes are only necessary at HVDD and HVSS pins." to " … with 2.5 kΩ to 5.0 kΩ series MELF-type resistor without the need of external TVS on evaluation boards, while protection diodes are necessary at HVDD and HVSS pins." NAFE11388 v.1 04 November 2022 Initial version
Table 49. Revision history...continued NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved.
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE Legal information Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term 'short data sheet' is explained in section "Definitions". [3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL https://www.nxp.com. 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NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE Quick reference data — The Quick reference data is an extract of the product data given in the Limiting values and Characteristics sections of this document, and as such is not complete, exhaustive or legally binding. Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from competent authorities. Suitability for use in non-automotive qualified products — Unless this document expressly states that this specific NXP Semiconductors product is automotive qualified, the product is not suitable for automotive use. It is neither qualified nor tested in accordance with automotive testing or application requirements. NXP Semiconductors accepts no liability for inclusion and/or use of non-automotive qualified products in automotive equipment or applications. In the event that customer uses the product for design-in and use in automotive applications to automotive specifications and standards, customer (a) shall use the product without NXP Semiconductors’ warranty of the product for such automotive applications, use and specifications, and (b) whenever customer uses the product for automotive applications beyond NXP Semiconductors’ specifications such use shall be solely at customer’s own risk, and (c) customer fully indemnifies NXP Semiconductors for any liability, damages or failed product claims resulting from customer design and use of the product for automotive applications beyond NXP Semiconductors’ standard warranty and NXP Semiconductors’ product specifications. Translations — A non-English (translated) version of a document, including the legal information in that document, is for reference only. The English version shall prevail in case of any discrepancy between the translated and English versions. Security — Customer understands that all NXP products may be subject to unidentified vulnerabilities or may support established security standards or specifications with known limitations. Customer is responsible for the design and operation of its applications and products throughout their lifecycles to reduce the effect of these vulnerabilities on customer’s applications and products. Customer’s responsibility also extends to other open and/or proprietary technologies supported by NXP products for use in customer’s applications. NXP accepts no liability for any vulnerability. Customer should regularly check security updates from NXP and follow up appropriately. Customer shall select products with security features that best meet rules, regulations, and standards of the intended application and make the ultimate design decisions regarding its products and is solely responsible for compliance with all legal, regulatory, and security related requirements concerning its products, regardless of any information or support that may be provided by NXP. NXP has a Product Security Incident Response Team (PSIRT) (reachable at PSIRT@nxp.com) that manages the investigation, reporting, and solution release to security vulnerabilities of NXP products. NXP B.V. — NXP B.V. is not an operating company and it does not distribute or sell products. Trademarks Notice: All referenced brands, product names, service names, and trademarks are the property of their respective owners. NXP — wordmark and logo are trademarks of NXP B.V. NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE Tables Tab. 29. 24-bit channel-based coefficient and data Tab. 30. System-level configurations and status Tab. 35. 24-bit HV input accuracy without factory Tab. 36. 24-bit HV input initial accuracy with Tab. 37. 24-bit HV input temperature and aging drift Tab. 38. 16-bit HV input accuracy without factory Tab. 40. 16-bit HV input temperature and aging drift Tab. 42. LV MUX inputs/GPIO0-GPIO1 as analog NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE Figures Fig. 2. Pin configuration in 64-lead 9 mm x 9 mm x Fig. 7. SINC Normal mode rejection vs frequency Fig. 14. Steps to setup for single-channel Fig. 15. Steps to setup for multichannel conversion Fig. 35. Host writes to register 16-bit with CRC Fig. 36. Host writes to register 24-bit with CRC Fig. 38. Conversion command data read operation 2/24-bit ADC, CRC_Enable = 1, Status_ Fig. 41. Conversion command data read operation 2/24-bit ADC, CRC_ENABLE = 1, Status_ Fig. 47. Package outline HVQFN64 Fig. 48. Package outline detail HVQFN64 Fig. 49. Reflow soldering footprint part 1 for Fig. 50. Reflow soldering footprint part 2 for NAFE11388 All information provided in this document is subject to legal disclaimers. © 2024 NXP B.V. All rights reserved. Product data sheet Rev. 4 — 2 April 2024
NXP Semiconductors NAFE11388 Universal ±25 V 8-Input Low Power AFE 7.9.2 24-bit channel-based coefficient and data
7.9.3 System-level configurations and status
11.4.1 HV input pin protection and HV supply
11.5.1.2 Voltage and current input gain and offset
Please be aware that important notices concerning this document and the product(s) described herein, have been included in section 'Legal information'. © 2024 NXP B.V. All rights reserved. For more information, please visit: https://www.nxp.com Date of release: 2 April 2024 Document identifier: NAFE11388