General Description

The G768D contains a precise digital thermometer, a fan controller, and a system-reset circuit.

Except for one less fan controller, G768D is backward compatible with G768B. G768D has 2 more functions, fan-failure detection and programmable thermal shutdown signal.

The thermometer reports the temperature of 2 remote sensors. The remote sensors are diode-connected transistors typically a low-cost, easily mounted 2N3904 NPN type that replace conventional thermistors or thermocouples. Remote accuracy is ±5°C for multiple transistor manufacturers, 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.

Features

■ Measures Two Remote Temperatures

■ No Calibration Required

■ SMBus 2-Wire Serial Interface

■ Programmable Under/Over-temperature Alarms

■ Programmable Thermal Shutdown Signal

■ Supports SMBus Alert Response

■ Accuracy:

±5°C (-40°C to + 125°C, remote)

±3°C (+60°C to + 100°C, remote)

■ +4.5V to +5.5V Supply Range

■ Fan speed control range: 3,000 to 30,000 rpm

■ Fan speed accuracy: ±2

■ Built-in MOSFET switch

■ Internal current-limit and over-temperature protection for fan control

■ Watchdog for fan control

■ Alarm for fan failure

■ Precision Monitoring of 5V Power-Supply Voltage

■ 340ms Typical Power-On Reset Pulse Width RESET Output

■ Guaranteed RESET Valid to VCC=1V

■ Power Supply Transient Immunity

■ No External Components needed for reset function

■ Small, 16-Pin SSOP Package

Applications

■ Desktop and Notebook

■ Central Office Computers

■ Telecom Equipment

■ Smart Battery Packs

■ Test and Measurement

■ LAN Servers

■ Multi-Chip Modules

■ Industrial Controls