General Description
The LM83 is a digital temperature sensor with a 2 wire serial
interface that senses the voltage and thus the temperature of
three remote diodes using a Delta-Sigma analog-to-digital
converter with a digital over-temperature detector. The LM83
accurately senses its own temperature as well as the temperature
of three external devices, such as Pentium II® Processors
or diode connected 2N3904s. The temperature of
any ASIC can be detected using the LM83 as long as a dedicated
diode (semiconductor junction) is available on the die.
Using the SMBus interface a host can access the LM83’s
registers at any time. Activation of a T_CRIT_A output occurs
when any temperature is greater than a programmable
comparator limit, T_CRIT. Activation of an INT output occurs
when any temperature is greater than its corresponding programmable
comparator HIGH limit.
The host can program as well as read back the state of the
T_CRIT register and the four T_HIGH registers. Three state
logic inputs allow two pins (ADD0, ADD1) to select up to 9
SMBus address locations for the LM83. The sensor powers
up with default thresholds of 127°C for T_CRIT and all
T_HIGHs. The LM83 is pin for pin and register compatible
with the LM84 as well as the Maxim MAX1617 and the Analog
Devices ADM1021.

Features
Accurately senses die temperature of 3 remote ICs, or
diode junctions
On-board local temperature sensing
SMBus and I2C compatible interface, supports
SMBus 1.1 TIMEOUT
Two interrupt outputs: INT and T_CRIT_A
Register readback capability
7 bit plus sign temperature data format, 1 °C resolution
2 address select pins allow connection of 9 LM83s on a
single bus

Key Specifications
Supply Voltage 3.0V to 3.6V
Supply Current 0.8mA (max)
Local Temp Accuracy (includes quantization error)
0°C to +85°C ±3.0°C (max)
Remote Diode Temp Accuracy (includes quantization
error)
+25°C to +100°C ±3°C (max)
0°C to +125°C ±4°C (max)

Applications
System Thermal Management
Computers
Electronic Test Equipment
Office Electronics
HVAC