This part is a kind of semiconductor called G781.

Function of this product has 1C Remote and Local Temperature Sensor with SMBus Serial Interface.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

Global Mixed-mode Technology Inc. ±1°C Remote and Local Temperature Sensor with SMBus Serial Interface Features „Two Channels: Measures Both Remote and G781 General Description The G781 is a precise digital thermometer that reports the temperature of both a remote sensor and its own package. The remote sensor is a diode-connected transistor typically a low-cost, easily mounted 2N3904 NPN type that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C with no calibration needed. The remote channel can also measure the die temperature of other ICs, such as microprocessors, that contain an on-chip, diode-connected transistor. The 2-wire serial interface accepts standard System Management Bus (SMBus) Write Byte, Read Byte, Send Byte, and Receive Byte commands to p [ ... ]

G781 PDF Datasheet Download