General Description

The G7951 contains 3 precise digital thermometers, one fan controllers, hardware and software thermal shutdown.

The thermometers report the temperature of 3 remote sensors. The remote sensors are diode-connected transistors typically a low-cost, easily mounted 2N3904 NPN type or the diode built-in in CPU. Remote accuracy is ±1°C for multiple transistor manufacturer. The G7951 also support offset adjust function via SMBus to fix the error due to different CPU diode or parasitic resistors.

The 2-wire serial interface accepts standard System Management Bus (SMBusTM) Write Byte, Read Byte, Send Byte, and Receive Byte commands. G7951 SMBus address is 7ah for write and 7bh for read. And supports writting protection function by command 20h to prevent error behavior of µP.

Features

● Measures Three Remote Temperatures

● Adjustable Offset for Each Sensor via SMBus

● Accuracy: ±1°C (+ 60°C to + 100°C)

±3°C (- 10°C to + 120°C)

● +4.5V to +5.5V Supply Range

● Programmable Hardware Thermal Shutdown for Sensor 2 and Programmable Software Thermal Shutdown for Sensor 1,3.

● SMBus 2-Wire Serial Interface with Writting Protection Function.

● Alert Signal for Diode Fault, Fan Fail, and Fan Out of Control

● Supports SMBus Alert Response

● PWM Mode Speed Control

● Closed Loop Speed Control and programmable 8 Bits Open Loop PWM Duty cycle Control for FAN

● Wide Speed Control Range for FAN, Accuracy within 2, when SET_CNT1 > 50

● Internal Current- limit and Over-temperature Protection for the Fan

● SSOP-16 & TQFN4X4-24 Package

Applications

● Desktop and Notebook

● Central Office Computers

● Telecom Equipment

● Smart Battery Packs

● Industrial Controls

● LAN Servers