Datasheet ADT7422 (Analog Devices)

±0.10°C Accuracy, 16-Bit, Digital I2C Temperature Sensor for VSM Applications Data Sheet ADT7422 FEATURES GENERAL DESCRIPTION Accuracy meets clinical thermometry specification of the
The ADT7422 is a high accuracy, digital I2C temperature sensor
ASTM E1112 when soldered onto the final PCB
designed to meet the clinical thermometry specification of the
±0.10°C from 25°C to 50°C at 3.0 V
ASTM E1112 standards when soldered onto the final printed
±0.25°C from −20°C to +105°C at 2.7 V to 3.3 V
circuit board (PCB).
Ultralow temperature drift: 0.0073°C
The ADT7422 contains an internal band gap reference, a
National Institute of Standards and Technology (NIST) traceable or equivalent
temperature sensor, and a precision analog-to-digital converter
Fast first temperature conversion at power-up of 6 ms
(ADC). The ADT7422 provides a 16-bit temperature result
Simple implementation
with a resolution of 0.0078°C and an accuracy of up to ±0.10°C
No temperature calibration or correction required
across the temperature range of 25°C to 50°C without the need
No linearity correction required
for calibration after the PCB soldering process.
Low power
Operating at 3.0 V, the average supply current is typically 210 μA.
140 μW typical at 3.0 V in 1 SPS mode
The ADT7422 has a shutdown mode that powers down the
6 μW typical at 3.0 V in shutdown mode
device and offers a shutdown current of typically 2.0 μA at 3.0 V.
Programmable interrupts
The ADT7422 is rated for operation over the −40°C to +125°C
Critical overtemperature interrupt
temperature range.
Overtemperature and undertemperature interrupt
Pin A0 and Pin A1 are available for address selection and provide
I2C-compatible interface
four possible I2C 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
APPLICATIONS
exceeds a programmable critical temperature limit. The INT pin is
Vital signs monitoring (VSM)
also an open-drain output that becomes active when the
Medical equipment
temperature exceeds a programmable limit. The INT pin and
Resistance temperature detector (RTD) and thermistor
CT pin can operate in comparator and interrupt event modes.
replacement PRODUCT HIGHLIGHTS Food transportation and storage Thermocouple cold junction compensation
1. No calibration or correction required by the user.
Environmental monitoring and heating, ventilation, and air
2. Low power consumption.
conditioning (HVAC)
3. Long-term stability and reliability.
Laser diode temperature control
4. High accuracy for industrial, instrumentation, and medical applications.
FUNCTIONAL BLOCK DIAGRAM INTERNAL 10 CT V 12 OSCILLATOR DD TCRIT INTERNAL REFERENCE 9 INT TEMPERATURE Σ-Δ GND 11 T SENSOR MODULATOR HIGH ADT7422 FILTER TLOW LOGIC A0 3 1 SCL I2C INTERFACE A1 4 2 SDA
001 61- 209 Figure 1.
Rev. 0 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. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2020 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS I2C TIMING SPECIFICATIONS Timing Diagram ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER DETAILS NORMAL MODE ONE SHOT MODE CT and INT Operation in One Shot Mode 1 SPS MODE SHUTDOWN MODE FAULT QUEUE TEMPERATURE DATA FORMAT TEMPERATURE CONVERSION FORMULAS 16-Bit Temperature Data Format 13-Bit Temperature Data Format 10-Bit Temperature Data Format 9-Bit Temperature Data Format REGISTERS ADDRESS POINTER REGISTER TEMPERATURE VALUE REGISTERS STATUS REGISTER CONFIGURATION REGISTER THIGH SETPOINT REGISTERS TLOW SETPOINT REGISTERS TCRIT SETPOINT REGISTERS THYST SETPOINT REGISTER ID REGISTER SERIAL INTERFACE SERIAL BUS ADDRESS WRITING DATA READING DATA RESET GENERAL CALL INT AND CT OUTPUTS UNDERTEMPERATURE AND OVERTEMPERATURE DETECTION Comparator Mode Interrupt Mode APPLICATIONS INFORMATION THERMAL RESPONSE TIME SUPPLY DECOUPLING POWERING FROM A SWITCHING REGULATOR TEMPERATURE MEASUREMENT QUICK GUIDE TO MEASURING TEMPERATURE OUTLINE DIMENSIONS ORDERING GUIDE