±0.25°C Accurate, 16-Bit Digital

I2C Temperature Sensor

Data Sheet

ADT7420

Rev. 0

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FEATURES

High performance

Temperature accuracy

±0.20°C from −10°C to +85°C at 3.0 V

±0.25°C from −20°C to +105°C from 2.7 V to 3.3 V

16-bit resolution: 0.0078°C

Ultralow temperature drift: 0.0073°C

NIST traceable or equivalent

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: −40°C to +150°C

Voltage range: 2.7 V to 5.5 V

Programmable interrupts

Critical overtemperature interrupt

Overtemperature/undertemperature interrupt

I2C-compatible interface

16-lead, 4 mm × 4 mm LFCSP RoHS-compliant package

APPLICATIONS

RTD and thermistor replacement

Thermocouple cold junction compensation

Medical equipment

Industrial control and test

Food transportation and storage

Environmental monitoring and HVAC

Laser diode temperature control

GENERAL DESCRIPTION

The ADT7420 is a high accuracy digital temperature sensor

offering breakthrough performance over a wide industrial range,

housed in a 4 mm × 4 mm LFCSP package. It contains an internal

band gap reference, a temperature sensor, and a 16-bit ADC to

monitor and digitize the temperature to 0.0078°C resolution.

The ADC resolution, by default, is set to 13 bits (0.0625°C).

The ADC resolution is a user programmable mode that can be

changed through the serial interface.

The ADT7420 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 ADT7420 has a shutdown mode that powers

down the device and offers a shutdown current of typically 2.0 μA

at 3.3 V. The ADT7420 is rated for operation over the −40°C to

+150°C temperature range.

Pin A0 and Pin A1 are available for address selection, giving the

ADT7420 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 INT pin is also

an open-drain output that becomes active when the tempera-

ture exceeds a programmable limit. The INT pin and CT pin

can operate in comparator and interrupt event modes.

PRODUCT HIGHLIGHTS

1.

Ease of use, no calibration or correction required by the user.

2.

Low power consumption.

3.

Excellent long-term stability and reliability.

4.

High accuracy for industrial, instrumentation, and medical

applications.

5.

Packaged in a 16-lead, 4 mm × 4 mm LFCSP RoHS-

compliant package.

FUNCTIONAL BLOCK DIAGRAM

INTERNAL

REFERENCE

POINTER

REGISTER

STATUS

REGISTER

12

11

TEMPERATURE

VALUE REGISTER

CONFIGURATION

REGISTER

THYST

REGISTER

TLOW

REGISTER

THIGH

REGISTER

TCRIT

REGISTER

SOFTWARE

RESET REGISTER

ID

REGISTER

TEMPERATURE

SENSOR

THIGH

TCRIT

TLOW

INTERNAL

OSCILLATOR

FILTER

LOGIC

MODULATOR

VDD

GND

10

9

CT

INT

3

4

A0

A1

1

2

SCL

SDA

I2C INTERFACE

ADT7420

Figure 1.