ADT7410 (Rev. C)
Document overview
- Manufacturer or author: Analog Devices, Inc.
- PDF pages: 24
Technical content
±0.5°C Accurate, 16-Bit Digital I2C Temperature Sensor Data Sheet ADT7410 Rev. C Document Feedback 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. Specifications subject to change without notice. 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 ©2009–2017 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com
FEATURES
±0.5°C from −40°C to +105°C (2.7 V to 3.6 V) ±0.4°C from −40°C to +105°C (3.0 V) 16-bit temperature resolution: 0.0078°C Fast first temperature conversion on power-up of 6 ms Easy implementation No temperature calibration/correction required by user No linearity correction required Low power Power saving 1 sample per second (SPS) mode 700 µW typical at 3.3 V in normal mode 7 µW typical at 3.3 V in shutdown mode Wide operating ranges Temperature range: −55°C to +150°C Voltage range: 2.7 V to 5.5 V Programmable interrupts Critical overtemperature interrupt Overtemperature/undertemperature interrupt I2C-compatible interface 8-lead narrow SOIC RoHS-compliant package
APPLICATIONS
Environmental control systems Computer thermal monitoring Thermal protection Industrial process control Power system monitors Hand-held applications GENERAL DESCRIPTION The ADT7410 is a high accuracy digital temperature sensor in a narrow SOIC package. It contains a band gap temperature reference and a 13-bit ADC to monitor and digitize the temperature to a 0.0625°C resolution. The ADC resolution, by default, is set to 13 bits (0.0625°C). This can be changed to 16 bits (0.0078°C) by setting Bit 7 in the configuration register (Register Address 0x03). The ADT7410 is guaranteed to operate over supply voltages from 2.7 V to 5.5 V . Operating at 3.3 V , the average supply current is typi- cally 210 μA. The ADT7410 has a shutdown mode that powers down the device and offers a shutdown current of typically 2 μA. The ADT7410 is rated for operation over the −55°C to +150°C temperature range. Pin A0 and Pin A1 are available for address selection, giving the ADT7410 four possible I2C addresses. The CT pin is an open- drain output that becomes active when the temperature exceeds a programmable critical temperature limit. The default critical temperature limit is 147°C. The INT pin is also an open-drain output that becomes active when the temperature exceeds a programmable limit. The INT and CT pins can operate in either comparator or interrupt mode. FUNCTIONAL BLOCK DIAGRAM TEMPERATURE VALUE REGISTER CONFIGURATION REGISTER THYST REGISTER TLOW REGISTER THIGH REGISTER TCRIT REGISTER POINTER REGISTER INTERNAL REFERENCE TEMPERATURE SENSOR THIGH TCRIT TLOW INTERNAL OSCILLATOR FILTER LOGIC Σ-Δ MODULATOR VDD GND CT INT SCL SDA I2C INTERFACE ADT7410 06560-001 Figure 1.
Rev. C | Page 2 of 24 TABLE OF CONTENTS
REVISION HISTORY
9/2017—Rev. B to Rev. C 7/2016—Rev. A to Rev. B 12/2011—Rev. 0 to Rev. A Changes to One-Shot Mode Section and 1 SPS Mode 4/2009—Revision 0: Initial Version
Rev. C | Page 3 of 24 SPECIFICATIONS TA = −55°C to +150°C, VDD = 2.7 V to 5.5 V , unless otherwise noted. Table 1. Parameter Min Typ Max Unit Test Conditions/Comments TEMPERATURE SENSOR AND ADC Accuracy1 −0.05 ±0.42 °C TA = −40°C to +105°C, VDD = 3.0 V ±0.44 °C TA = −40°C to +105°C, VDD = 2.7 V to 3.3 V ±0.5 °C TA = −55°C to +125°C, VDD = 3.0 V ±0.5 °C TA = −40°C to +105°C, VDD = 2.7 V to 3.6 V ±0.7 °C TA = −55°C to +150°C, VDD = 2.7 V to 3.6 V ±0.8 °C TA = −40°C to +105°C, VDD = 4.5 V to 5.5 V ±1.0 °C TA = −55°C to +150°C, VDD = 2.7 V to 5.5 V ADC Resolution 13 Bits Twos complement temperature value of the sign bit plus 12 ADC bits (power-up default resolution)
16 Bits Twos complement temperature value of the sign bit
plus 15 ADC bits (Bit 7 = 1 in the configuration register) Temperature Resolution 13-Bit 0.0625 °C 13-bit resolution (sign + 12-bit) 16-Bit 0.0078 °C 16-bit resolution (sign + 15-bit) Temperature Conversion Time 240 ms Continuous conversion and one-shot conversion modes Fast Temperature Conversion Time 6 ms First conversion on power-up only
1 SPS Conversion Time 60 ms Conversion time for 1 SPS mode
Temperature Hysteresis ±0.002 °C Temperature cycle = 25°C to 125°C and back to 25°C Repeatability3 ±0.015 °C TA = 25°C DC PSRR 0.1 °C/V TA = 25°C DIGITAL OUTPUTS (OPEN DRAIN) High Output Leakage Current, IOH 0.1 5 µA CT and INT pins pulled up to 5.5 V Output High Current 1 mA VOH = 5.5 V Output Low Voltage, VOL 0.4 V IOL = 2 mA at 5.5 V, IOL = 1 mA at 3.3 V Output High Voltage, VOH 0.7 × VDD V Output Capacitance, COUT 3 pF DIGITAL INPUTS Input Current ±1 µA VIN = 0 V to VDD Input Low Voltage, VIL 0.4 V Input High Voltage, VIH 0.7 × VDD V SCL, SDA Glitch Rejection 50 ns Input filtering suppresses noise spikes of less than 50 ns Pin Capacitance 5 10 pF POWER REQUIREMENTS Supply Voltage 2.7 5.5 V Supply Current At 3.3 V 210 250 µA Peak current while converting, I2C interface inactive At 5.5 V 250 300 µA Peak current while converting, I2C interface inactive
1 SPS Current
At 3.3 V 46 µA VDD = 3.3 V, 1 SPS mode, TA = 25°C At 5.5 V 65 µA VDD = 5.5 V, 1 SPS mode, TA = 25°C Shutdown Current At 3.3 V 2.0 15 µA Supply current in shutdown mode At 5.5 V 5.2 25 µA Supply current in shutdown mode Power Dissipation Normal Mode 700 µW VDD = 3.3 V, normal mode at 25°C Power Dissipation 1 SPS 150 µW Power dissipated for VDD = 3.3 V, TA = 25°C 1 Accuracy includes lifetime drift. 2 The equivalent 3 σ limits are ±0.33°C. This 3 σ specification is provided to enable comparison with other vendors who use these limits. 3 Based on a floating average of 10 readings.
(10% to 90% of VDD) and timed from a voltage level of 1.6 V . 1 Sample tested during initial release to ensure compliance. 2 All input signals are specified with input rise/fall times = 3 ns, measured between the 10% and 90% points. Timing reference points at 50% for inputs and outputs. Figure 2. Serial Interface Timing Diagram
vs. ambient temperature (TA).
3 Junction-to-case resistance is applicable to components featuring a
Figure 3. SOIC_N Maximum Power Dissipation vs. Temperature
Figure 4. Pin Configuration Table 4. Pin Function Descriptions the ADT7410. Open-drain configuration. A pull-up resistor is required, typically 10 kΩ. configuration. A pull-up resistor is required, typically 10 kΩ. 3 A0 I 2C Serial Bus Address Selection Pin. Logic input. Connect to GND or VDD to set an I2C address. 4 A1 I 2C Serial Bus Address Selection Pin. Logic input. Connect to GND or VDD to set an I2C address. active low comparator interrupt. Open-drain configuration. A pull-up resistor is required, typically 10 kΩ. configuration. A pull-up resistor is required, typically 10 kΩ. 7 GND Analog and Digital Ground.
and input to a precision digital modulator. needing correction or calibration by the user. Figure 12. Σ-Δ Modulator low. Fast conversion temperature accuracy is typically within ±5°C.
to reduce power consumption. register (Register Address 0x03) to 01. to power up and complete a conversion. configuration register (Register Address 0x03) to 01.
1 SPS MODE
In this mode, the part performs one measurement per second. any register resets the INT and CT pins. configuration register, Register Address 0x03) resets the INT pin. Address 0x03) resets the CT pin. See Figure 13. rate is appropriate to the application being used. CONVERSION TIME. THE DELAY IS 60ms IN THE CASE OF A 1 SPS CONVERSION. Figure 13. One-Shot CT Pin
Rev. C | Page 11 of 24 SHUTDOWN The ADT7410 can be placed in shutdown mode by writing 1 to Bit 6 and 1 to Bit 5 of the configuration register (Register Address 0x03), in which case the entire IC is shut down and no further conversions are initiated until the ADT7410 is taken out of shutdown mode. The ADT7410 can be taken out of shutdown mode by writing 0 to Bit 6 and 0 to Bit 5 in the configuration register (Register Address 0x03). The ADT7410 typically takes 1 ms (with a 0.1 µF decoupling capacitor) to come out of shutdown mode. The conversion result from the last conversion prior to shutdown can still be read from the ADT7410 even when it is in shutdown mode. When the part is taken out of shutdown mode, the internal clock is started and a conversion is initiated. FAULT QUEUE Bit 0 and Bit 1 of the configuration register (Register Address 0x03) are used to set up a fault queue. The queue can facilitate up to four fault events to prevent false tripping of the INT and CT pins when the ADT7410 is used in a noisy temperature environment. The number of faults set in the queue must occur consecutively to set the INT and CT outputs. For example, if the number of faults set in the queue is four, then four consecutive temperature conversions must occur with each result exceeding a temperature limit in any of the limit registers before the INT and CT pins are activated. If two consecutive temperature conversions exceed a temperature limit and the third conversion does not, the fault count is reset back to zero.
One LSB of the ADC corresponds to 0.0625°C in 13-bit mode. temperature limit stored in the TLOW setpoint register. shows the 13-bit temperature data format without Bit 0 to Bit 2. power-on default setting has a 13-bit temperature data value. Table 5. 13-Bit Temperature Data Format where Bit 15 (sign bit) is removed from the ADC code. where Bit 15 (sign bit) is removed from the ADC code. where Bit 9 (sign bit) is removed from the ADC code. where Bit 8 (sign bit) is removed from the ADC code.
- Nine temperature registers
- A status register
- An ID register
- A configuration register
- An address pointer register
- A software reset All registers are eight bits wide. The temperature value registers, the status register, and the ID register are read-only. The software reset is a write-only register. On power-up, the address pointer register is loaded with 0x00 and points to the temperature value register MSB.
Table 6. ADT7410 Registers shows the register address of each register on the ADT7410. The default value of the address pointer register is 0x00. Table 7. Address Pointer Register temperature measured by the internal temperature sensor. address (Register Address 0x01). and are instead used as the LSB bits for the extended digital value. Table 8. Temperature Value MSB Register (Register Address 0x00) Table 9. Temperature Value LSB Register (Register Address 0x01) 0x03[4]. When the temperature value is below TLOW, this bit it set to 1. register, Register Address 0x03[7] = 1 (16-bit resolution). register, Register Address 0x03[7] = 1 (16-bit resolution). 0x03[4]. When the temperature value exceeds TCRIT, this bit it set to 1. register, Register Address 0x03[7] = 1 (16-bit resolution). [7:3] 00000 R Temp Temperature value in twos complement format.
RDY bit is reset after a write to the one-shot bits. interrupt pins polarity, and overtemperature fault queues. Table 10. Status Register (Register Address 0x02) [3:0] 0000 R Unused Reads back 0. the limit set in the setpoint TLOW + THYST registers. below the limit set in the setpoint THIGH − THYST registers. below the limit set in the setpoint TCRIT − THYST registers. SPS modes, this bit is reset after a write to the one-shot bits. Table 11. Configuration Register (Register Address 0x03) 2 0 R/W CT pin polarity This bit selects the output polarity of the CT pin. 3 0 R/W INT pin polarity This bit selects the output polarity of the INT pin. 4 0 R/W INT/CT mode This bit selects between comparator mode and interrupt mode. [6:5] 00 R/W Operation mode These two bits set the operational mode for the ADT7410. 01 = one shot. Conversion time is typically 240 ms. reduces the average current consumption. 11 = shutdown. All circuitry except interface circuitry is powered down. 7 0 R/W Resolution This bit sets up the resolution of the ADC when converting. 0 = 13-bit resolution. Sign bit + 12 bits gives a temperature resolution of 0.0625°C. 1 = 16-bit resolution. Sign bit + 15 bits gives a temperature resolution of 0.0078°C.
increments to Register Address 0x05 (THIGH setpoint LSB). The default setting for the THIGH setpoint is 64°C. being the temperature sign bit. increments to Register Address 0x07 (TLOW setpoint LSB). The default setting for the TLOW setpoint is 10°C. format with the MSB being the temperature sign bit. auto-increments to Register Address 0x09 (TCRIT setpoint LSB). The default setting for the TCRIT limit is 147°C. Table 12. THIGH Setpoint MSB Register (Register Address 0x04) [15:8] 0x20 R/W THIGH MSB MSBs of the overtemperature limit, stored in twos complement format. Table 13. THIGH Setpoint LSB Register (Register Address 0x05) [7:0] 0x00 R/W THIGH LSB LSBs of the overtemperature limit, stored in twos complement format. Table 14. TLOW Setpoint MSB Register (Register Address 0x06) [15:8] 0x05 R/W TLOW MSB MSBs of the undertemperature limit, stored in twos complement format. Table 15. TLOW Setpoint LSB Register (Register Address 0x07) [7:0] 0x00 R/W TLOW LSB LSBs of the undertemperature limit, stored in twos complement format. Table 16. TCRIT Setpoint MSB Register (Register Address 0x08) [15:8] 0x49 R/W TCRIT MSB MSBs of the critical overtemperature limit, stored in twos complement format. Table 17. TCRIT Setpoint LSB Register (Register Address 0x09) [7:0] 0x80 R/W TCRIT LSB LSBs of the critical overtemperature limit, stored in twos complement format.
to Bit 7 and the silicon revision in Bit 0 to Bit 2. Table 18. THYST Setpoint Register (Register Address 0x0A) [3:0] 0101 R/W THYST Hysteresis value, from 0°C to 15°C. Stored in straight binary format. The default setting is 5°C. Table 19. ID Register (Register Address 0x0B)
address pointer register to set up the relevant register address. values upload for approximately 200 µs. The reset command address word is 0x2F. address and reads in the following data byte. default values upload for approximately 200 µs. Figure 17. Reading Back Data from the Configuration Register
- A START CONDITION AT THE BEGINNING IS DEFINED AS A HIGH-TO-LOW TRANSITION ON SDA WHILE SCLK REMAINS HIGH.
- A STOP CONDITION AT THE END IS DEFINED AS A LOW-TO-HIGH TRANSITION ON SDA WHILE SCLK REMAINS HIGH.
- THE MASTER GENERATES THE NO ACKNOWLEDGE AT THE END OF THE READBACK TO SIGNAL THAT IT DOES NOT WANT ADDITIONAL DATA.
- TEMPERATURE REGISTER MSB DATA AND TEMPERATURE REGISTER LSB DATA ARE ALWAYS SEPARATED BY A LOW ACK BIT.
- THE R/W BIT IS SET TO A1 TO INDICATE A READBACK OPERATION.
1 A1 A0
0 A1 A0
01 A1 A0
Figure 18. Reading Back Data from the Temperature Value Register
Figure 20. INT Output Temperature Response Diagram for TLOW Undertemperature Events
best to determine the settling time empirically. might seem convenient to tap into the digital logic power supply. amplitude due to wiring resistance and inductance. Figure 21. Use of Separate Traces to Reduce Power Supply Noise affect nearby integrated circuits. and the GND of the heat source be reduced as much as possible.
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure 22. 8-Lead Standard Small Outline Package [SOIC_N] 2 Maximum accuracy over the −40°C to +105°C temperature range. I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors). registered trademarks are the property of their respective owners.