Datasheet ADT7312 (Analog Devices)

Automotive, ±1°C Accurate, 16-Bit, 175°C, Digital SPI Temperature Sensor in Die Form Data Sheet ADT7312 FEATURES GENERAL DESCRIPTION Qualified for automotive applications
The ADT7312 is a ±1°C accurate digital temperature sensor
High performance
that operates over a very wide temperature range of −55°C to
Temperature accuracy:
+175°C and is available in die form only. It contains an internal
±1°C from −55°C to +175°C (2.7 V to 3.3 V)
band gap reference, a temperature sensor, and a 16-bit analog-
16-bit temperature resolution: 0.0078°C
to-digital converter (ADC) to monitor and digitize the temper-
Fast first temperature conversion on power-up of 6 ms
ature to a resolution of 0.0078°C. The default ADC resolution
Easy implementation
is 13 bits (0.0625°C). The ADC resolution can be changed to
No temperature calibration or correction required
16 bits (0.0078°C) using the serial interface.
No linearity correction required
The ADT7312 is guaranteed to operate over supply voltages
Low power
from 2.7 V to 5.5 V. At 3.6 V operation, the average supply
Power-saving 1 sample per second (SPS) mode
current is typically 245 μA. The ADT7312 has a shutdown
880 μW typical at 3.6 V in normal mode
mode that powers down the device, resulting in a typical
9 μW typical at 3.6 V in shutdown mode
shutdown current of 2.5 μA at 3.6 V. The ADT7312 is rated
Wide operating ranges
for operation over the −55°C to +175°C temperature range.
Temperature range: −55°C to +175°C Voltage range: 2.7 V to 5.5 V
The CT pin is an open-drain output that becomes active when
Programmable interrupts
the temperature exceeds a programmable critical temperature
Critical overtemperature interrupt
limit. The default critical temperature limit is 147°C. The INT
Overtemperature/undertemperature interrupt
pin is also an open-drain output that becomes active when the
SPI-compatible interface
temperature exceeds a programmable limit. The INT pin and
Available in die form only
the CT pin can operate in either comparator or interrupt mode.
APPLICATIONS PRODUCT HIGHLIGHTS Automotive
1. Ease of use, no calibration or correction required.
High temperature monitoring
2. Low power consumption.
High temperature thermal protection
3. Excellent long-term stability and reliability. 4. Qualified for automotive applications.
FUNCTIONAL BLOCK DIAGRAM ADT7312 INTERNAL INTERNAL REFERENCE OSCILLATOR SCLK 1 6 CT TCRIT E C DOUT 2 A F TEMPERATURE Σ-∆ ER T SENSOR MODULATOR 5 INT DIN 3 N I I THIGH SP CS 4 FILTER 7 GND LOGIC TLOW 8 GND CONFIGURATION T T STATUS CRIT LOW REGISTER REGISTER REGISTER REGISTER 9 VDD 10 V TEMPERATURE DD T T ID VALUE HYST HIGH
1
REGISTER REGISTER REGISTER REGISTER
-00 6791 0 Figure 1.
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Document Outline Features Applications General Description Product Highlights Functional Block Diagram Table of Contents Revision History Specifications SPI Timing Specifications Absolute Maximum Ratings ESD Caution Pad Configuration and Function Descriptions Die Bond Pad Coordinates Typical Performance Characteristics Theory of Operation Circuit Description Converter Architecture Normal Mode (Continuous Conversion 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 Status Register Configuration Register Temperature Value Register ID Register TCRIT Setpoint Register THYST Setpoint Register THIGH Setpoint Register TLOW Setpoint Register Serial Interface SPI Command Byte Writing Data Reading Data Interfacing to DSPs or Microcontrollers Resetting the Serial Interface INT and CT Outputs Undertemperature and Overtemperature Detection Comparator Mode Interrupt Mode Redundant Critical Generator Applications Information Thermal Response Time Supply Decoupling Powering from a Switching Regulator Temperature Monitoring Quick Guide to Measuring Temperature Outline Dimensions Ordering Guide Automotive Products