GENERAL DESCRIPTION

The W83781D/G is a hardware monitoring IC for personal computers, server computers, or microprocessor based systems. W83781D/G can be used to monitor several critical hardware parameters of the system, including power supply voltages, fan speeds, and temperatures, which are very important for a high-end computer system to work stablely and properly. W83781D provides both ISA and I2CTM serial bus interface.

A 8-bit analog-to-digital converter (ADC) was built inside W83781D/G. The W83781D/G can monitor 3 external thermistor temperature sensors, 5 positive analog voltage inputs, two inverting inputs (for monitoring negative voltages), and also three fan tachometer outputs. There is also one input for case open detection circuits.

FEATURES

Monitoring Items

• 3 thermal inputs from remote thermistors

• 5 positive voltage inputs (typical for +12V, +5V, +3.3V, VcoreA, VcoreB)

• 2 op amps for negative voltage monitoring (typical for -12V, -5V)

• 3 fan speed monitoring inputs

• Case open detection input

• WATCHDOG comparison of all monitored values

• Programmable hysteresis and setting points for all monitored items

Actions Enabling

• Warning signal pop up in application software

• Beep tone warning

• Fan ON/OFF control

• Issue SMI#, IRQ to activate system protection

General

• ISA and I2CTM serial bus interface

• 5 VID input pins for CPU Vcore identification

• Initial power fault beep (for +3.3V, VcoreA)

• Master reset input to W83781D/G

• Independent power plane of digital Vcc and analog Vcc (input to IC)

• Intel LDCMTM compatible

• Winbond monitoring application software support

• Input clock rate optional for 24, 48, 14.318 MHz

Package

• 48-pin LQFP