General Description
The MAX31732 is a multi-channel temperature sensor
that monitors its own temperature and the temperatures
of up to four external diode-connected transistors. A
resistance cancellation feature compensates for up to
300Ω of series resistance between the external thermal
diode and the MAX31732, while beta compensation
corrects for temperature-measurement errors due to
low-beta sensing transistors. The sensor also allows
ideality factors between 0.9844 and 1.311.
The MAX31732 offers two open-drain, active-low
alarm outputs, ALARM1 and ALARM2. When the
measured temperature of a channel crosses the
respective primary overtemperature/undertemperature
threshold levels, ALARM1 asserts low, and a status bit
is set in the corresponding thermal status registers.
When the measured temperature of a channel crosses
the secondary overtemperature/undertemperature
threshold levels, ALARM2 asserts low and a status bit is
set in the corresponding thermal status registers. The
highest temperature register allows the controller to
obtain the temperature of the hottest channel.
A 512-bit nonvolatile memory (NVM) allows the
MAX31732 to program the configuration registers during
power-up without software/firmware intervention. The
NVM also captures the fault temperature for each
remote and local channel for further analysis at a later
time.
The 2-wire serial interface accepts SMBus protocols
(write byte, read byte, send byte, and receive byte) for
reading the temperature data and programming the
temperature thresholds. Any one of the eight available
target addresses can be selected using the address
selection input (ADD), which can be connected to
ground or connected to a grounded resistor.
The is specified over the -40°C to +125°C operating
temperature range and with a 3.0V to 3.6V input supply
range. MAX31732 is available in a 24-pin, 4mm x 4mm
TQFN package.

Features
• One Local and Four Remote Temperature-Sensing
Channels
• ±1°C Remote Temperature-Measurement Accuracy
(-40°C to +125°C)
• -64°C to +150°C Remote Temperature-
Measurement Range
• Up to 300Ω Resistance Cancellation for Remote
Channels
• Compensation for Low Beta Transistors
• 12 Bit, 0.0625°C Resolution
• Two Programmable Alarm Temperature Thresholds
• Eight Selectable Target Addresses
• Flexible I2C/SMBus Interfaces to a Variety of
Microcontrollers
• Ideality Factor of up to 1.311
• NVM Facilitates Configuration and Fault Logging

Applications
• Temperature Measurement of On-Chip CPU, ASIC,
SOC, or FPGA diodes or remote discrete diodes
• Industrial-Thermal Management