1FEATURES

2• Accurately Senses Die Temperature of 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

LM82s on a Single Bus

APPLICATIONS

• System Thermal Management

• Computers

• Electronic Test Equipment

• Office Electronics

• HVAC

KEY SPECIFICATIONS

• Supply Voltage: 3.0 to 3.6V

• Supply Current: 0.8mA (max)

• Local Temp Accuracy (includes quantization

error):

– 0 to +85 ±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)

DESCRIPTION

The LM82 is a digital temperature sensor with a 2

wire serial interface that senses the voltage and thus

the temperature of a remote diode using a Delta-

Sigma analog-to-digital converter with a digital over-

temperature detector. The LM82 accurately senses

its own temperature as well as the temperature of

external devices, such as Pentium II Processors or

diode connected 2N3904s. The temperature of any

ASIC can be detected using the LM82 as long as a

dedicated diode (semiconductor junction) is available

on the die. Using the SMBus interface a host can

access the LM82'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 2 T_HIGH registers.

Three state logic inputs allow two pins (ADD0, ADD1) to select up to 9 SMBus address locations for the

LM82. The sensor powers up with default thresholds

of 127°C for T_CRIT and all T_HIGHs. The LM82 is

pin for pin and register compatible with the LM84,

Maxim MAX1617 and Analog Devices ADM1021.