±0.25°C Accurate, 16-Bit

Digital SPI Temperature Sensor

Preliminary Technical Data

ADT7320

Rev. PrA

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FEATURES

Temperature accuracy ±0.25°C from −20°C to +105°C

13- or 16-bit user-selectable temperature-to-digital

converter

Low drift silicon temperature sensor

No temperature calibration/correction required by user

Power saving 1 sample per second (SPS) mode

Fast first conversion on power-up of 6 ms

SPI-compatible interface

Operating temperature from −40°C to +150°C

Operating voltage: 2.7 V to 5.5 V

Critical overtemperature indicator

Programmable overtemperature/undertemperature interrupt

Low power consumption: 700 μW typical at 3.3 V

Shutdown mode for lower power: 7 μW typical at 3.3 V

16-lead RoHS-compliant LFCSP package

APPLICATIONS

RTD and thermistor replacement

Medical equipment

Cold junction compensation

Industrial controls and test

Food transportation and storage

Environmental monitoring and HVAC

GENERAL DESCRIPTION

The ADT7320 is a high accuracy digital temperature sensor

offering breakthrough performance over a wide industrial range,

housed in an LFCSP package. It contains a band gap temperature

reference and a 13-bit analog-to-digital converter (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 0x01).

The ADT7320 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

typically 210 μA. The ADT7320 has a shutdown mode that

powers down the device and offers a shutdown current of

typically 2 μA. The ADT7320 is rated for operation over the

−40°C to +150°C temperature range.

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

INTERNAL

REFERENCE

8

7

TEMPERATURE

SENSOR

INTERNAL

OSCILLATOR

FILTER

LOGIC

MODULATOR

GND

6

5

CT

INT

3

4

1

2

ADT7320

CS

TEMPERATURE

VALUE

REGISTER

CONFIGURATION

AND STATUS

REGISTERS

REGISTER

REGISTER

REGISTER

REGISTER

SCLK

DOUT

DIN

Figure 1.