Datasheet
±0.25°C Accurate, 16-Bit Digital
I
2
C 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
I
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C-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 I
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C 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
T
HYST
REGISTER
T
LOW
REGISTER
T
HIGH
REGISTER
T
CRIT
REGISTER
SOFTWARE
RESET REGISTER
ID
REGISTER
TEMPERATURE
SENSOR
T
HIGH
T
CRIT
T
LOW
INTERNAL
OSCILLATOR
FILTER
LOGIC
Σ-Δ
MODULATOR
V
DD
GND
10
9
CT
INT
3
4
A0
A1
1
2
SCL
SDA
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C INTERFACE
ADT7420
09013-001
Figure 1.