LM82  Product Folder

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.

• 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

• System Thermal Management
• Computers
• Electronic Test Equipment
• Office Electronics
• HVAC