DESCRIPTION

The LTC®690 family provides complete power supply monitoring and battery control functions for microprocessor reset, battery back-up, CMOS RAM write protection, power failure warning and watchdog timing. A precise internal voltage reference and comparator circuit monitor the power supply line. When an out-of-tolerance condition occurs, the reset outputs are forced to active states and the chip enable output unconditionally write-protects external memory. In addition, the RESET output is guaranteed to remain logic low even with VCC as low as 1V.

FEATURES

■ Guaranteed Reset Assertion at VCC = 1V
■ 1.5mA Maximum Supply Current
■ Fast (35ns Max) Onboard Gating of RAM Chip Enable Signals
■ SO-8 and S16 Packaging
■ 4.65V Precision Voltage Monitor
■ Power OK/Reset Time Delay: 50ms, 200ms or Adjustable
■ Minimum External Component Count
■ 1µA Maximum Standby Current
■ Voltage Monitor for Power-Fail or Low-Battery Warning
■ Thermal Limiting
■ Performance Specifi ed Over Temperature
■ Superior Upgrade for MAX690 Family

APPLICATIONS

■ Critical μP Power Monitoring
■ Intelligent Instruments
■ Battery-Powered Computers and Controllers
■ Automotive Systems