G781

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 cali-bration needed. The remote channel of G781 can also meas-ure the die temperature of other ICs, such as micro-processors, 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 program the alarm thresholds and to read temperature data. The data format of G781 is 11bits plus sign, with each bit cor-responding to 0.125°C, in two's-complement format. Measurements can be done automatically and autonomously, with the conversion rate programmed by the user or programmed to operate in a single-shot mode. The adjustable rate of G781 allows the user to control the supply current drain.

The G781 is available in a small, 8-pin SOP sur-face-mount package.