ADT7420_12 Datasheet, PDF (1/24 Pages) Analog Devices – ±0.25°C Accurate, 16-Bit Digital I2C Temperature Sensor

Data Sheet
±0.25°C Accurate, 16-Bit Digital
I²C Temperature Sensor
ADT7420
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.
V_DD 12
A0 3
A1 4
CONFIGURATION
REGISTER
T_LOW
REGISTER
T_HYST
REGISTER
ID
REGISTER
SOFTWARE
RESET REGISTER
FUNCTIONAL BLOCK DIAGRAM
TEMPERATURE
VALUE REGISTER
T_CRIT
REGISTER
T_HIGH
REGISTER
STATUS
REGISTER
POINTER
REGISTER
INTERNAL
REFERENCE
TEMPERATURE
SENSOR
ADT7420
INTERNAL
OSCILLATOR
Σ-Δ
MODULATOR
FILTER
LOGIC
I²C INTERFACE
11
GND
Figure 1.
T_CRIT
T_HIGH
T_LOW
10 CT
9 INT
1 SCL
2 SDA
Rev. 0
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