View mic281 datasheet:

MIC281 Micrel MIC281 Low-Cost IttyBitty™ Thermal Sensor Final Information General Description Features The MIC281 is a digital thermal sensor capable of measuring • Remote temperature measurement using embedded the temperature of a remote PN junction. It is optimized for thermal diodes or commodity transistors applications favoring low cost and small size. The remote • Accurate remote sensing junction may be an inexpensive commodity transistor, e.g., ±3°C max., 0°C to 100°C 2N3906, or an embedded thermal diode such as found in Intel • Excellent noise rejection Pentium* II/III/IV CPUs, AMD Athlon* CPUs, and Xilinx • I2C and SMBus 2.0 compatible serial interface Virtex* FPGAs. • SMBus timeout to prevent bus lockup • Voltage tolerant I/Os The MIC281 is 100% software and hardware