AD7417ACHIPS

AD7416 AD | Alldatasheet

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REV. G AD7416/AD7417/AD7418 10-Bit Digital Temperature Sensor (AD7416) and Four Single-Channel ADCs (AD7417/AD7418) Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 © 2004 Analog Devices, Inc. All rights reserved.

FEATURES

10-Bit ADC with 15 /H9262s and 30 /H9262s Conversion Times Single and Four Single-Ended Analog Input Channels On-Chip Temperature Sensor: –40 /H11543C to +125 /H11543C On-Chip Track-and-Hold Overtemperature Indicator Automatic Power-Down at the End of a Conversion Wide Operating Supply Range: 2.7 V to 5.5 V I 2C® Compatible Serial Interface Selectable Serial Bus Address Allows Connection of up to Eight AD7416/AD7417s to a Single Bus AD7416 Is a Superior Replacement for LM75

APPLICATIONS

Data Acquisition with Ambient Temperature Monitoring Industrial Process Control Automotive Battery-Charging Applications Personal Computers FUNCTIONAL BLOCK DIAGRAMS VDD OTI GND SDA SCL FAULT QUEUE COUNTER SETPOINT COMPARATORTOTI SETPOINT REGISTER THYST SETPOINT REGISTER TEMPERATURE VALUE REGISTER CONFIGURATION REGISTER SERIAL BUS INTERFACE BAND GAP TEMPERATURE SENSOR 10-BIT ANALOG-DIGITAL CONVERTER ADDRESS POINTER REGISTER AD7416 CONTROL LOGIC A > B REFIN VDD OTI SCL SDA A2A1A0CONVST AIN1 AIN2 AIN3 AIN4 TEMP SENSOR SAMPLING CAPACITOR VBALANCE CLOCK A B REF 2.5V CHARGE DISTRIBUTION DAC I2C INTERFACE MUX OVERTEMP REG NC NC GND DATA OUT NC = NO CONNECT AD7417 CONTROL LOGIC A > B VDD OTI SCL SDA AIN1 SAMPLING CAPACITOR VBALANCE CLOCK A B I2C INTERFACE MUX OVERTEMP REG GND DATA OUT TEMP SENSOR REFIN CONVST REF 2.5V CHARGE DISTRIBUTION DAC AD7418 GENERAL DESCRIPTION The AD7417 and AD7418 are 10-bit, 4-channel and single- channel ADCs with an on-chip temperature sensor that can operate from a single 2.7 V to 5.5 V power supply. The devices contain a 15 µs successive approximation converter, a 5-channel multiplexer, a temperature sensor, a clock oscilla- tor, a track-and-hold, and a reference (2.5 V). The AD7416 is a temperature-monitoring only device in an 8-lead package. The temperature sensor on the parts can be accessed via multi- plexer Channel 0. When Channel 0 is selected and a conversion is initiated, the resulting ADC code at the end of the conversion gives a measurement of the ambient temperature (±1°C @ 25°C). On-chip registers can be programmed with high and low tem- perature limits, and an open-drain overtemperature indicator (OTI) output is provided, which becomes active when a pro- grammed limit is exceeded. A configuration register allows programming of the sense of the OTI output (active high or active low) and its operating mode (comparator or interrupt). A programmable fault queue counter allows the number of out-of-limit measurements that must occur before triggering the OTI output to be set to prevent spurious triggering of the OTI output in noisy environments. (continued on page 7)

REV. G–2– AD7416/AD7417/AD7418 (VDD = 2.7 V to 5.5 V, GND = 0 V, REF IN = 2.5 V, unless otherwise noted.) Parameter A Version B Version 1 Unit Test Conditions/Comments DC ACCURACY Any Channel. Resolution 10 10 Bits Minimum Resolution for Which No Missing Codes Are Guaranteed 10 10 Bits Relative Accuracy2 ± 1 ± 1L SB max This Specification Is Typical for V DD of 3.6 V to 5.5 V. Differential Nonlinearity 2 ± 1 ± 1L SB max This Specification Is Typical for V DD of 3.6 V to 5.5 V. Gain Error2 ± 3 ± 3L SB max External Reference. ± 10 ± 10 LSB max Internal Reference. Gain Error Match2 ± 0.6 ± 0.6 LSB max AD7417 Only. Offset Error2 ± 4 ± 4L S B m a x Offset Error Match ± 0.7 ± 0.7 LSB max AD7417 Only. ANALOG INPUTS Input Voltage Range V REF VREF V max

00 V min

Input Leakage Current 3 ± 1 ± 1 µA max Input Capacitance 10 10 pF max TEMPERATURE SENSOR1 Measurement Error Ambient Temperature 25 °C ± 2 ± 1 °C max TMIN to TMAX ± 3 ± 2 °C max Temperature Resolution 1/4 1/4 °C/LSB CONVERSION RATE Track-and-Hold Acquisition Time 4 400 400 ns max Source Impedance < 10 Ω. Conversion Time Temperature Sensor 30 30 µs max Typically 27 µs. Channels 1 to 4 15 15 µs max Typically 10 µs. REFERENCE INPUT5, 6 REFIN Input Voltage Range6 2.625 2.625 V max 2.5 V + 5%. 2.375 2.375 V min 2.5 V – 5%. Input Impedance 40 40 k Ω min Input Capacitance 10 10 pF max ON-CHIP REFERENCE Nominal 2.5 V. Reference Error6 ± 25 ± 25 mV max Temperature Coefficient 6 80 80 ppm/ °C typ DIGITAL INPUTS Input High Voltage, V IH VDD × 0.7 V DD × 0.7 V min Input Low Voltage, V IL VDD × 0.3 V DD × 0.3 V max Input Leakage Current 1 1 µA max DIGITAL OUTPUTS Output Low Voltage, V OL 0.4 0.4 V max I OL = 3 mA. Output High Current 1 1 µA max V OH = 5 V. POWER REQUIREMENTS VDD 5.5 5.5 V max For Specified Performance. 2.7 2.7 V min IDD Logic Inputs = 0 V or V DD. Normal Operation 600 600 µA max Power-Down 1 1 µA max 50 nA Typically. Auto Power-Down Mode V DD = 3 V. See Operating Modes.

10 SPS Throughput Rate 6 6 µW typ

1 kSPS Throughput Rate 60 60 µW typ 10 kSPS Throughput Rate 600 600 µW typ Power-Down 3 3 µW max Typically 0.15 µW. AD7417/AD7418–SPECIFICATIONS

and temperature sensor measurement error = ±3°C. 3Refers to the input current when the part is not converting. Primarily due to reverse leakage current in the ESD protection dio des. 4Sample tested during initial release and after any redesign or process change that may affect this parameter. 5On-chip reference shuts down when external reference is applied. 6The accuracy of the temperature sensor is affected by reference tolerance. The relationship between the two is explained in the Temperature Sensor section. Specifications subject to change without notice. 1For VDD = 2.7 V to 3 V, T A max = 85°C and accuracy = ±3°C. 2Sample tested during initial release and after any redesign or process change that may affect this parameter. Specifications subject to change without notice. Figure 1. Diagram for Serial Bus Timing

REV. G–4– AD7416/AD7417/AD7418 AD7417 PIN FUNCTION DESCRIPTION Pin No. Mnemonic Description 1, 16 NC No Connection. Do not connect anything to this pin. 2 SDA Digital I/O. Serial bus bidirectional data. Push-pull output. 3 SCL Digital Input. Serial bus clock. 4 OTI This is a logic output. The overtemperature indicator (OTI) is set if the result of a conversion on Channel 0 (temperature sensor) is greater than an 8-bit word in the overtemperature register (OTR). The signal is reset at the end of a serial read operation. Open-drain output. 5 REFIN Reference Input. An external 2.5 V reference can be connected to the AD7417 at this pin. To enable the on-chip reference, the REFIN pin should be tied to GND. If an external reference is connected to the AD7417, the internal reference will shut down. 6G ND Ground reference for track-and-hold, comparator and capacitor DAC, and digital circuitry. 7–10 A IN1 to AIN4 Analog Input Channels. The AD7417 has four analog input channels. The input channels are single-ended with respect to GND. The input channels can convert voltage signals in the range 0 V to V REF. A chan- nel is selected by writing to the configuration register of the AD7417. (See Control Byte section.) 11 A2 Digital Input. The highest programmable bit of the serial bus address. 12 A1 Digital Input. The middle programmable bit of the serial bus address. 13 A0 Digital Input. The lowest programmable bit of the serial bus address. 14 V DD Positive Supply Voltage, 2.7 V to 5.5 V. 15 CONVST Logic Input Signal. Convert start signal. The rising edge of this signal fully powers up the part. The power-up time for the part is 4 µs. If the CONVST pulse is greater than 4 µs, the falling edge of CONVST places the track-and-hold mode into hold mode and initiates a conversion. If the pulse is less than 4 µs, an internal timer ensures that the track-and-hold does not go into hold and conversion is not initiated until the power-up time has elapsed. The track-and-hold goes into track mode again at the end of con- version. (See Operating Mode section.) AD7417 PIN CONFIGURATION SOIC/TSSOP TOP VIEW (Not to Scale) NC = NO CONNECT NC SDA SCL OTI REFIN GND AIN1 AIN2 NC CONVST VDD AIN4 AIN3 AD7417

REV. G AD7416/AD7417/AD7418 –5– AD7416 PIN FUNCTION DESCRIPTION Pin No. Mnemonic Description 1 SDA Digital I/O. Serial bus bidirectional data. Push-pull output. 2 SCL Digital Input. Serial bus clock. 3 OTI This is a logic output. The OTI is set if the result of a conversion on Channel 0 (temperature sensor) is greater that an 8-bit word in the OTR. The signal is reset at the end of a serial read operation. Open- drain output. 4G ND Ground reference for track-and-hold, comparator and capacitor DAC, and digital circuitry. 5A 2D igital Input. The highest programmable bit of the serial bus address. 6A 1D igital Input. The middle programmable bit of the serial bus address. 7A 0D igital Input. The lowest programmable bit of the serial bus address. 8V DD Positive Supply Voltage, 2.7 V to 5.5 V. AD7418 PIN FUNCTION DESCRIPTION Pin No. Mnemonic Description 1 SDA Digital I/O. Serial bus bidirectional data. Push-pull output. 2 SCL Digital Input. Serial bus clock. 3 OTI This is a logic output. The OTI is set if the result of a conversion on Channel 0 (temperature sensor) is greater that an 8-bit word in the OTR. The signal is reset at the end of a serial read operation. Open- drain output. 4G ND Ground reference for track-and-hold, comparator and capacitor DAC, and digital circuitry. 5A IN Analog Input Channel. The input channel is single-ended with respect to GND. The input channel can convert voltage signals in the range 0 V to V REF. The analog input channel is selected by writing to the configuration register of the AD7418 and choosing Channel 4. (See Control Byte section.) 6 REFIN Reference Input. An external 2.5 V reference can be connected to the AD7418 at this pin. To enable the on-chip reference, the REF IN pin should be tied to GND. If an external reference is connected to the AD7418, the internal reference will shut down. 7V DD Positive Supply Voltage, 2.7 V to 5.5 V. 8 CONVST Logic Input Signal. Convert start signal. The rising edge of this signal fully powers up the part. The power-up time for the part is 4 µs. If the CONVST pulse is greater than 4 µs, the falling edge of CONVST places the track-and-hold mode into hold mode and initiates a conversion. If the pulse is less than 4 µs, an internal timer ensures that the track-and-hold does not go into hold and conversion is not initiated until the power-up time has elapsed. The track-and-hold goes into track mode again at the end of conversion. (See Operating Mode section.) AD7416 PIN CONFIGURATION SOIC/MSOP TOP VIEW (Not to Scale) SDA SCL OTI GND VDD AD7416 AD7418 PIN CONFIGURATION SOIC/MSOP TOP VIEW (Not to Scale) SDA SCL OTI GND CONVST VDD REFIN AIN AD7418

REV. G–6– AD7416/AD7417/AD7418 ABSOLUTE MAXIMUM RATINGS 1 (TA = 25°C, unless otherwise noted.) Analog Input Voltage to AGND Reference Input Voltage to AGND 2 . . –0.3 V to VDD + 0.3 V Operating Temperature Range Lead Temperature, Soldering Lead Temperature, Soldering Lead Temperature, Soldering NOTES

1 Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 If the reference input voltage is likely to exceed V DD by more than 0.3 V (e.g., during power-up) and the reference is capable of supplying 30 mA or more, it is recommended to use a clamping diode between the REF IN pin and VDD pin. The diagram below shows how the diode should be connected. REFIN VDD AD7417 BAT81 CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7416/AD7417/AD7418 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

REV. G AD7416/AD7417/AD7418 –7– ORDERING GUIDE Temperature Temperature Package Package Model Range Error Description Branding Option AD7416ACHIPS Die AD7416AR –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416AR-REEL –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416AR-REEL7 –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416ARZ* –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416ARZ-REEL * –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416ARZ-REEL7 * –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7416ARM –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7416ARM-REEL –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7416ARM-REEL7 –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7416ARMZ* –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7416ARMZ-REEL * –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7416ARMZ-REEL7 * –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C6A RM-8 AD7417ACHIPS Die AD7417AR –40°C to +125°C ± 2°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7417AR-REEL –40°C to +125°C ± 2°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7417AR-REEL7 –40°C to +125°C ± 2°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7417ARU –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 AD7417ARU-REEL –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 AD7417ARU-REEL7 –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 AD7417BR –40°C to +85°C ± 1°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7417BR-REEL –40°C to +85°C ± 1°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7417BR-REEL7 –40°C to +85°C ± 1°C 16-Lead Standard Small Outline Package (SOIC) RN-16 AD7418ACHIPS Die AD7418AR –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7418AR-REEL –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7418AR-REEL7 –40°C to +125°C ± 2°C 8-Lead Standard Small Outline Package (SOIC) RN-8 AD7418ARM –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C7A RM-8 AD7418ARM-REEL –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C7A RM-8 AD7418ARM-REEL7 –40°C to +125°C ± 2°C 8-Lead Micro Small Outline Package (MSOP) C7A RM-8 AD7418ARUZ* –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 AD7418ARUZ-REEL * –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 AD7418ARUZ-REEL7 * –40°C to +125°C ± 2°C 16-Lead Thin Shrink Small Outline Package (TSSOP) RU-16 EVAL-AD7416/AD7417/ Evaluation Board AD7418EB *Pb-Free Part

REV. G–8– AD7416/AD7417/AD7418 (continued from page 1) An I2C compatible serial interface allows the AD7416/AD7417/ AD7418 registers to be written to and read back. The three LSBs of the AD7416/AD7417 ’s serial bus address can be selected, which allows up to eight AD7416/AD7417s to be connected to a single bus. The AD7417 is available in a narrow body, 0.15'', 16-lead, small outline IC (SOIC) and in a 16-lead, thin shrink, small outline package (TSSOP). The AD7416 and AD7418 are available in 8-lead SOIC and MSOP packages. PRODUCT HIGHLIGHTS 1. The AD7416/AD7417/AD7418 have an on-chip temperature sensor that allows an accurate measurement of the ambient temperature (±1°C @ 25°C, ± 2°C overtemperature) to be made. The measurable temperature range is –40°C to +125°C. An overtemperature indicator is implemented by carrying out a digital comparison of the ADC code for Channel 0 (temperature sensor) with the contents of the on-chip over- temperature register. 2. The AD7417 offers a space-saving 10-bit A/D solution with four external voltage input channels, an on-chip temperature sensor, an on-chip reference, and clock oscillator. 3. The automatic power-down feature enables the AD7416/ AD7417/AD7418 to achieve superior power performance. At slower throughput rates, the part can be programmed to operate in a low power shutdown mode, allowing further savings in power consumption. TERMINOLOGY Relative Accuracy Relative accuracy or endpoint nonlinearity is the maximum deviation from a straight line passing through the endpoints of the ADC transfer function. Differential Nonlinearity This is the difference between the measured and the ideal 1 LSB change between any two adjacent codes in the ADC. Offset Error This is the deviation of the first code transition (0000 . . . 000) Offset Error Match This is the difference in offset error between any two channels. Gain Error This is the deviation of the last code transition (1111 . . . 110) offset error has been adjusted out. Gain Error Match This is the difference in gain error between any two channels. Track-and-Hold Acquisition Time Track-and-hold acquisition time is the time required for the output of the track-and-hold amplifier to reach its final value, within ±1/2 LSB, after the end of conversion (the point at which the track-and-hold returns to track mode). It also applies to situations where a change in the selected input channel takes place or where there is a step input change on the input voltage applied to the selected A IN input of the AD7417 or AD7418. It means that the user must wait for the duration of the track-and- hold acquisition time after the end of conversion or after a channel change/step input change to A IN before starting another conver- sion, to ensure that the part operates to specification. CIRCUIT INFORMATION The AD7417 and AD7418 are single-channel and four-channel, 15 µs conversion time, 10-bit ADCs with on-chip temperature sensor, reference, and serial interface logic functions on a single chip. The AD7416 has no analog input channel and is intended for temperature measurement only. The ADC section consists of a conventional successive approximation converter based around a capacitor DAC. The AD7416, AD7417, and AD7418 are capable of running on a 2.7 V to 5.5 V power supply, and the AD7417 and AD7418 accept an analog input range of 0 V to +VREF. The on-chip temperature sensor allows an accurate measurement of the ambient device temperature to be made. The working measurement range of the temperature sensor is –40°C to +125°C. The parts require a 2.5 V reference that can be provided from the part ’s own internal reference or from an external reference source. CONVERTER DETAILS Conversion is initiated on the AD7417/AD7418 by pulsing the CONVST input. The conversion clock for the part is internally generated so no external clock is required except when reading from and writing to the serial port. The on-chip track-and-hold goes from track to hold mode and the conversion sequence is started on the falling edge of the CONVST signal. A conversion is also initiated in the automatic conversion mode every time a read or write operation to the AD7416/AD7417/AD7418 takes place. In this case, the internal clock oscillator (which runs the automatic conversion sequence) is restarted at the end of the read or write operation. The track-and-hold goes into hold approximately 3 µs after the read or write operation is complete and a conversion is then initiated. The result of the conversion is available either 15 µs or 30 µs later, depending on whether an analog input channel or the temperature sensor is selected. The track-and-hold acquisition time of the AD7417/AD7418 is 400 ns. A temperature measurement is made by selecting the Channel 0 of the on-chip mux and carrying out a conversion on this channel. A conversion on Channel 0 takes 30 µs to complete. Tempera- ture measurement is explained in the Temperature Measurement section of this data sheet. The on-chip reference is not available to the user, but REF IN can be overdriven by an external reference source (2.5 V only). All unused analog inputs should be tied to a voltage within the nominal analog input range to avoid noise pickup. For mini- mum power consumption, the unused analog inputs should be tied to GND.

Figure 2 shows a typical connection diagram for the AD7417.

2.5 V reference can be connected at the REF

Operating Modes section of this data sheet. Figure 2. Typical Connection Diagram the ADC sampling capacitor and has a capacitance of 3 pF. Figure 3. Equivalent Analog Input Circuit sion. Therefore, the on-chip reference is not available externally. An external 2.5 V reference can be connected to the REF IN pin. This has the effect of shutting down the on-chip reference circuitry. Figure 4. On-Chip Reference BE, which varies from device to device. q is the charge on the electron (1.6 × 10-19 Coulombs). T is the absolute temperature in Kelvins. N is the ratio of the two currents. Figure 5. Temperature Measurement Technique

three LSBs of this register are used to select a data register. 10-bit twos complement format. Bits 5 to 0 are unused. to the operating temperature range of the device. output in 10-bit twos complement form.

10 MSBs of this word store the temperature measurement (see

1. Positive Temperature = ADC Code/ 4
2. Negative Temperature = (ADC Code * – 512)/4

*MSB is removed from the ADC Code. Figure 6. Six of these are data registers and one is an Address ADC and Config2 Registers are not applicable to the AD7416). Figure 6. AD7417/AD7418 Register Structure

selects the shutdown mode (Default D0 = 0). Register. Bits 6 to 0 are unused. Register. Bits 6 to 0 are unused.

10 MSBs store the value produced by the ADC in binary for-

Register with 10 MSBs containing the ADC conversion request.

1. The ideal transfer function characteristic for the AD7417

and AD7418 ADC is shown in Figure 7. Figure 7. Ideal Transfer Function Characteristic when the CONVST pin is used. Bit 6 contains the Test 1 Bit. master device, e.g., the processor.

REV. G–14– AD7416/AD7417/AD7418 Please note that when reading back from the ADT7416/ ADT7417/ADT7418, no more than three bytes of data must be read back. A STOP command must be inserted at the end of the read communication. If a STOP command is not inserted by the master and the ADT7416/ADT7417/ADT7418 receives more SCL cycles than the maximum needed for three bytes of data, then the I 2C interface on the ADT7416/ADT7417/ ADT7418 will pull the SDA line low and prevent it from going high again. To recover the ADT7416/ADT7417/ADT7418 interface the part must be powered off and on again. Reference the application note, AN-686, on the Analog Devices website for more information on I 2C interfaces. OTI OUTPUT The OTI output has two operating modes, which are selected by Bit D1 of the Configuration Register. In the comparator mode, (D1 = 0), the OTI output becomes active when the temperature exceeds T OTI and remains active until the tempera- ture falls below T HYST. This mode allows the AD7416/AD7417/ AD7418 to be used as a thermostat, for example, to control the operation of a cooling fan. TOTI THYST OTI OUTPUT COMPARATOR MODE OTI OUTPUT INTERRUPT MODE READ* READ* READ* READ* READ* READ* READ* IN INTERRUPT MODE, A READ OPERATION OR SHUTDOWN RESETS THE OTI OUTPUT; OTHERWISE THE OTI OUTPUT REMAINS ACTIVE INDEFINITELY, ONCE TRIGGERED. *Figure 13. Operation of OTI Output (Shown Active Low) The open-drain configuration of OTI allows the OTI outputs of several AD7416/AD7417/AD7418s to be wire-ANDed together when in active low mode. The OTI output is used to indicate that an out-of-limit tem- perature excursion has occurred. OTI is an open-drain output that can be programmed to be active low by setting Bit D2 of the Configuration Register to 0 or active high by setting Bit D2 of the Configuration Register to 1. In the interrupt mode (D1 = 1), the OTI output becomes active when the temperature exceeds T OTI and remains active even if the temperature falls below THYST, until it is reset by a read opera- tion. Once OTI has become active by the temperature exceeding TOTI, and has then been reset, it will remain inactive even if the temperature remains, or subsequently rises again, above TOTI. It will not become active again until the temperature falls below T HYST. It will then remain active until reset by a read opera- tion. Once OTI has become active by the temperature falling below THYST and then reset, it will remain inactive even if the temperature remains, or subsequently falls again, below T HYST. OTI is also reset when the AD7416/AD7417/AD7418 is placed in shutdown mode by setting Bit D0 of the Configuration Regis- ter to 1. The OTI output requires an external pull-up resistor. This can be connected to a voltage different from V DD (for example, to allow interfacing between 5 V and 3.3 V systems) provided that the maximum voltage rating of the OTI output is not exceeded. The value of the pull-up resistor depends on the application but should be as large as possible to avoid excessive sink currents at the OTI output, which can heat the chip and affect the tempera- ture reading. The maximum value of the pull-up resistor that will meet the output high current specification of the OTI out- put is 30 k Ω, but higher values may be used if a lower output current is required. For most applications, a value of 10 k Ω will prove suitable. FAULT QUEUE To avoid false triggering of the AD7416/AD7417/AD7418 in noisy environments, a fault queue counter is provided that can be programmed by Bits D3 and D4 of the Configuration Regis- ter (see Table V) to count 1, 2, 4, or 6 fault events before OTI becomes active. In order to trigger OTI, the faults must occur consecutively. For example, if the fault queue is set to 4, then four consecutive temperature measurements greater than T OTI (or less than T HYST) must occur. Any reading that breaks the sequence will reset the fault queue counter, so if there are three readings greater than TOTI followed by a reading less than TOTI, the fault queue counter will be reset without triggering OTI. POWER-ON DEFAULTS The AD7416/AD7417/AD7418 always powers up with the following defaults. Address pointer pointing to Temperature Value Register com- parator mode T OTI = 80°C THYST = 75°C OTI Active LOW Fault Queue = 1 These default settings allow the AD7416/AD7417/AD7418 to be used as a standalone thermostat without any connection to a serial bus. OPERATING MODES The AD7416/AD7417/AD7418 has two possible modes of operation depending on the value of D0 in the Configuration Register. Mode 1 Normal operation of the AD7416/AD7417/AD7418 occurs when D0 = 0. In this active mode, a conversion takes place every 400 µs. Once the conversion has taken place, the part partially powers down, consuming typically 350 µA of the current until the next conversion occurs. Two situations can arise in this mode on the request of a tempera- ture read. If a read occurs during a conversion, the conversion aborts and a new one starts on the stop/repeat start condition. The temperature value that is read is that of the previous com- pleted conversion. The next conversion will typically occur 400 µs after the new conversion has begun. If a read is called between conversions, a conversion is initiated on the stop/repeat start condition. After this conversion, the part returns to performing a conversion every 400 µs.

REV. G AD7416/AD7417/AD7418 –17– OUTLINE DIMENSIONS Purchase of licensed I 2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Phi lips I 2C Patent Rights to use these components in an I 2C system, provided that the system conforms to the I 2C Standard Specification as defined by Philips. 16-Lead Standard Small Outline Package [SOIC] Narrow Body (R-16) Dimensions shown in millimeters and (inches) CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MS-012AC 16 9 4.00 (0.1575) 3.80 (0.1496) 10.00 (0.3937) 9.80 (0.3858) 1.27 (0.0500) BSC 6.20 (0.2441) 5.80 (0.2283) SEATING PLANE 0.25 (0.0098) 0.10 (0.0039) 0.51 (0.0201) 0.31 (0.0122) 1.75 (0.0689) 1.35 (0.0531) 8/H11543 0/H11543 0.50 (0.0197) 0.25 (0.0098) 1.27 (0.0500) 0.40 (0.0157) COPLANARITY 0.10 /H11547 45/H11543 0.25 (0.0098) 0.17 (0.0067) 16-Lead Thin Shrink Small Outline Package [TSSOP] (RU-16) Dimensions shown in millimeters 16 9 PIN 1 SEATING PLANE 8/H11543 0/H11543 4.50 4.40 4.30 6.40 BSC 5.10 5.00 4.90 0.65 BSC 0.15 0.05 1.20 MAX 0.20 0.09 0.75 0.60 0.45 0.30 0.19 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-153AB 8-Lead Standard Small Outline Package [SOIC] Narrow Body (R-8) Dimensions shown in millimeters and (inches) 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) /H11547 45/H11543 8/H11543 0/H11543 1.75 (0.0688) 1.35 (0.0532) SEATING PLANE 0.25 (0.0098) 0.10 (0.0040) 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) BSC 6.20 (0.2440) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122)COPLANARITY 0.10 CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN COMPLIANT TO JEDEC STANDARDS MS-012AA 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters 0.80 0.60 0.40 8/H11543 0/H11543 4.90 BSC PIN 1

0.65 BSC

3.00 BSC SEATING PLANE 0.15 0.00 0.38 0.22

1.10 MAX

3.00 BSC COPLANARITY 0.10 0.23 0.08 COMPLIANT TO JEDEC STANDARDS MO-187AA

REV. G–18– AD7416/AD7417/AD7418

Revision History

8/04—Data Sheet Changed from REV. F to REV. G. 7/03–Data Sheet Changed from REV. E to REV. F. 10/02–Data Sheet Changed from REV. D to REV. E.

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C01126–0–8/04(G) –20–