LM83 Datasheet | National Semiconductor

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 parator limit, T_CRIT. Activation of an INT output occurs when any temperature is greater than its corresponding programmable parator 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 patible with the LM84 as well as the Maxim MAX1617 and the Analog Devices ADM1021. n On-board local temperature sensing n SMBus and I2C patible interface, supports SMBus 1.1 TIMEOUT n Two interrupt outputs: INT and T_CRIT_A n Register readback capability n 7 bit plus sign temperature data format, 1 ˚C resolution n 2 address select pins allow connection of 9 LM83s on a single bus Key Specifications n Supply Voltage n Supply Current 0˚C to +85˚C 3.0V to 3.6V 0.8m A (max) n Local Temp Accuracy (includes quantization error) ± 3.0˚C (max) n Remote Diode Temp Accuracy (includes quantization error) +25˚C to +100˚C 0˚C to +125˚C ± 3˚C (max) ± 4˚C (max) Applications n n n n n System Thermal Management puters Electronic Test Equipment Office Electronics HVAC Features n Accurately senses die...