ADT7408 Datasheet, PDF (1/24 Pages) Analog Devices – +-2 C Accurate, 12-Bit Digital Temperature Sensor

FEATURES
12-bit temperature-to-digital converter
±2°C accuracy
Operation from −20°C to +125°C
Operation from 3 V to 3.6 V
240 μA typical average supply current
Selectable 1.5°C, 3°C, 6°C hysteresis
SMBus-/I²C®-compatible interface
Dual-purpose event pin: comparator or interrupt
8-lead LFCSP_VD, 3 mm × 3 mm (JEDEC MO-229 VEED-4)
package
Complies with JEDEC standard JC-42.4 memory module
Thermal sensor component specification
APPLICATIONS
Memory module temperature monitoring
Isolated sensors
Environmental control systems
Computer thermal monitoring
Thermal protection
Industrial process control
Power system monitors
GENERAL DESCRIPTION
The ADT7408 is the first digital temperature sensor that complies
with JEDEC standard JC-42.4 for the mobile platform memory
module. The ADT7408 contains a band gap temperature sensor
and a 12-bit ADC to monitor and digitize the temperature to a
resolution of 0.0625°C.
There is an open-drain EVENT# output that is active when the
monitoring temperature exceeds a critical programmable limit or
when the temperature falls above or below an alarm window.
This pin can operate in either comparator or interrupt mode.
There are three slave device address pins that allow up to eight
ADT7408s to be used in a system that monitors temperature of
various components and subsystems.
±2°C Accurate, 12-Bit Digital
Temperature Sensor
ADT7408
FUNCTIONAL BLOCK DIAGRAM
DECIMATOR
V_DD
8
12- / 10-Bit
DIGITAL COMPARATOR
–
7 EVENT#
TEMPERATURE
SENSOR
LPF
+
1-BIT
+
REFERENCE
CLK
AND TIMING
GENERATION
–
∑-∆
1-BIT
DAC
ADDRESS
POINTER
REGISTER
ADT7408
MANUFACTURER’S
ID REGISTER
FACTORY
RESERVED
REGISTER
CAPABILITY
REGISTER
CONFIGURATION
REGISTER
ALARM TEMP
UPPER
BOUNDARY TRIP
REGISTER
ALARM TEMP
LOWER
BOUNDARY TRIP
REGISTER
CRITICAL TEMP
REGISTER
TEMPERATURE
REGISTER
A0 1
A1 2
A2 3
SMBus/I²C INTERFACE
4
V_ss
5 SDA
6 SCL
Figure 1.
The ADT7408 is specified for operation at supply voltages from
3.0 V to 3.6 V. Operating at 3.3 V, the average supply current is
less than 240 μA typical. The ADT7408 offers a shutdown mode
that powers down the device and gives a shutdown current of 3 μA
typical. The ADT7408 is rated for operation over the −20°C to
+125°C temperature range. The ADT7408 is available in a lead-
free, 8-lead LFCSP_VD, 3 mm × 3 mm (JEDEC MO-229 VEED-4)
package.
Rev. 0
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