The LM89 is an 11-bit digital temperature sensor with a
2-wire System Management Bus (SMBus) serial interface.
The LM89 accurately measures its own temperature as well
as the temperature of an external device, such as processor
thermal diode or diode-connected transistor such as the
2N3904. The temperature of any ASIC can be accurately
determined using the LM89 as long as a dedicated diode
(semiconductor junction) is available on the target die. The
LM89 remote sensor accuracy of ±0.75°C is factory trimmed
for the series resistance and 1.0021 typical non-ideality factor
of the Intel? Pentium? 4 and the Mobile Pentium 4
Processor-M thermal diode. The LM89 has an Offset
register to allow measuring other diodes without
requiring continuous software management. Contact
to obtain the latest data for
new processors.