General Description

The MAX690 family of supervisory circuits reduces the complexity and number of components required for power supply monitoring and battery control functions in microprocessor systems. These include µP reset and backup-battery switchover, watchdog timer, CMOS RAM write protection, and power-failure warning. The MAX690 family significantly improves system reliability and accuracy compared to that obtainable with separate ICs or discrete components.

Benefts and Features

● Supervisory Function Integration Saves Board Space while Fully Protecting Microprocessor-Based Systems

    • Precision Voltage Monitor

        - 4.65V (MAX690, MAX691, MAX694, MAX695)

        - 4.40V (MAX692, MAX693)

    • Power OK/Reset Time Delay

        - 50ms, 200ms, or Adjustable

    • Watchdog Timer

        - 100ms, 1.6s, or Adjustable

    • Battery Backup Power Switching

    • Voltage Monitor for Power Fail or Low Battery Warning

    • Minimum External Component Count

● Low Power Consumption in Battery Backup Mode Extends Battery Life

    • 1µA Standby Current

● Onboard Gating of Chip Enable Signals Protects Against Erroneous Data Written to RAM During Low VCC Events

Applications

● Computers

● Controllers

● Intelligent Instruments

● Automotive Systems

● Critical µP Power Monitoring