General Description

The G690/G691 are microprocessor (µP) supervisory circuits used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V- powered circuits.

These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available.

Features

■ Precision Monitoring of +3V, +3.3V, and +5V Power-Supply Voltages

■ Fully Specified Over Temperature

■ Available in Three Output Configurations

   Push-Pull RESET Output (G690L)

   Push-Pull RESET Output (G690H)

   Open-Drain RESET Output (G691L)

■ 140ms min Power-On Reset Pulse Width

■ 10µA Supply Current

■ Guaranteed Reset Valid to VCC = +1V

■ Power Supply Transient Immunity

■ No External Components

■ 3-Pin SOT-23 and SC-70-3(SOT-323) Packages

Applications

■ Computers

■ Controllers

■ Intelligent Instruments

■ Critical µP and µC Power Monitoring

■ Portable / Battery-Powered Equipment

■ Automotive