2 0.1C Accuracy, 16-Bit, Digital I C Temperature Sensor for VSM Applications Data Sheet ADT7422 FEATURES GENERAL DESCRIPTION Accuracy meets clinical thermometry specification of the 2 The ADT7422 is a high accuracy, digital I C temperature sensor ASTM E1112 when soldered onto the final PCB designed to meet the clinical thermometry specification of the 0.1C from 25C to 50C at 3.0 V ASTM E1112 standards when soldered onto the final printed 0.25C from 20C to +105C at 2.7 V to 3.3 V circuit board (PCB). Ultralow temperature drift: 0.0073C The ADT7422 contains an internal band gap reference, a National Institute of Standards and Technology (NIST) temperature sensor, and a precision analog-to-digital converter traceable or equivalent (ADC). The ADT7422 provides a 16-bit temperature result Fast first temperature conversion at power-up of 6 ms with a resolution of 0.0078C and an accuracy of up to 0.1C Simple implementation across the temperature range of 25C to 50C without the need No temperature calibration or correction required for calibration after the PCB soldering process. No linearity correction required Low power Operating at 3.0 V, the average supply current is typically 210 A. 140 W typical at 3.0 V in 1 SPS mode The ADT7422 has a shutdown mode that powers down the 6 W typical at 3.0 V in shutdown mode device and offers a shutdown current of typically 2.0 A at 3.0 V. Programmable interrupts The ADT7422 is rated for operation over the 40C to +125C Critical overtemperature interrupt temperature range. Overtemperature and undertemperature interrupt Pin A0 and Pin A1 are available for address selection and provide 2 I C-compatible interface 2 four possible I C addresses for the ADT7422. The CT pin is an 16-lead, 4 mm 4 mm, RoHS compliant LFCSP open-drain output that becomes active when the temperature exceeds a programmable critical temperature limit. The INT pin is APPLICATIONS also an open-drain output that becomes active when the Vital signs monitoring (VSM) temperature exceeds a programmable limit. The INT pin and Medical equipment CT pin can operate in comparator and interrupt event modes. Resistance temperature detector (RTD) and thermistor replacement PRODUCT HIGHLIGHTS Food transportation and storage 1. No calibration or correction required by the user. Thermocouple cold junction compensation 2. Low power consumption. Environmental monitoring and heating, ventilation, and air 3. Long-term stability and reliability. conditioning (HVAC) 4. High accuracy for industrial, instrumentation, and medical Laser diode temperature control applications. FUNCTIONAL BLOCK DIAGRAM INTERNAL 10 CT OSCILLATOR V 12 DD T CRIT INTERNAL REFERENCE 9 INT - TEMPERATURE T 11 HIGH GND MODULATOR SENSOR ADT7422 FILTER T LOW LOGIC A0 3 1 SCL 2 I C INTERFACE 4 2 SDA A1 Figure 1. Rev. A 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. Tel: 781.329.4700 2020 Analog Devices, Inc. All rights reserved. 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. Technical Support www.analog.com 20961-001ADT7422 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Temperature Value Registers ................................................... 13 Applications ...................................................................................... 1 Status Register ............................................................................. 14 General Description ......................................................................... 1 Configuration Register .............................................................. 14 Product Highlights ........................................................................... 1 THIGH Setpoint Registers ............................................................. 15 Functional Block Diagram .............................................................. 1 T Setpoint Registers ............................................................. 15 LOW Revision History ............................................................................... 2 T Setpoint Registers ............................................................. 10 CRIT Specifications .................................................................................... 3 T Setpoint Register .............................................................. 15 HYST 2 I C Timing Specifications ............................................................ 4 ID Register .................................................................................. 15 Absolute Maximum Ratings ........................................................... 5 Serial Interface ................................................................................ 16 Thermal Resistance ...................................................................... 5 Serial Bus Address ...................................................................... 16 ESD Caution.................................................................................. 5 Writing Data ............................................................................... 17 Pin Configuration and Function Descriptions ............................ 6 Reading Data ............................................................................... 18 Typical Performance Characteristics ............................................. 7 Reset ............................................................................................. 19 Theory of Operation ........................................................................ 9 General Call ................................................................................ 19 Circuit Information ..................................................................... 9 INT and CT Outputs ..................................................................... 20 Converter Details ......................................................................... 9 Undertemperature and Overtemperature Detection ............ 20 Normal Mode ................................................................................ 9 Applications Information ............................................................. 22 One Shot Mode ............................................................................. 9 Thermal Response Time ........................................................... 22 1 SPS Mode .................................................................................. 11 Supply Decoupling ..................................................................... 22 Shutdown Mode ......................................................................... 11 Powering from a Switching Regulator .................................... 22 Fault Queue ................................................................................. 11 Temperature Measurement ...................................................... 22 Temperature Data Format ........................................................ 12 Quick Guide to Measuring Temperature ............................... 22 Temperature Conversion Formulas ........................................ 12 Outline Dimensions ....................................................................... 23 Registers ........................................................................................... 13 Ordering Guide .......................................................................... 23 Address Pointer Register ........................................................... 13 REVISION HISTORY 4/2020Rev. 0 to Rev. A Changes to Data Sheet Title, Features Section, and General Description Section .......................................................................... 1 Change to Accuracy Parameter, Table 1 ....................................... 3 1/2020Revision 0: Initial Version Rev. A Page 2 of 23