The LM95231 is a precision dual remote diode temperature
sensor (RDTS) that uses National’s TruTherm technology.
The 2-wire serial interface of the LM95231 is compatible with
SMBus 2.0. The LM95231 can sense three temperature
zones, it can measure the temperature of its own die as well
as two diode connected transistors. The LM95231 includes
digital filtering and an advanced input stage that includes
analog filtering and TruTherm technology that reduces
processor-to-processor non-ideality spread. The diode connected
transistors can be a “thermal diode” as found in Intel
and AMD processors or can simply be a diode connected
MMBT3904 transistor. TruTherm technology allows accurate
measurement of “thermal diodes” found on small geometry
processes, 90nm and below. The LM95231 supports user
selectable thermal diode non-ideality of either a Pentium? 4
processor on 90nm process or 2N3904.