MICROPROCESSOR UP WATCH DOG TIMERE

DESCRIPTION

The UTC UWD813 microprocessor supervisory circuit reduces

the complexity and number of components required to monitor

power-supply and monitor microprocessor activity. It significantly

improves system reliability and accuracy compared to separate ICs

or discrete components.

The UTC UWD813 provides power-supply monitoring circuitry

that generates a reset output during power-up, power-down and

brownout conditions. The reset output remains operational with

VCC as low as 1V. Independent watchdog monitoring circuitry is

also provided. This is activated if the watchdog input has not been

toggled within 1.9 seconds.

In addition, there is a 1.25V threshold detector for power-fail

warning, low-battery detection, or monitoring an additional power

supply. An active-low manual-reset input (MR ) is also included.

FEATURES

* Precision supply- Voltage Monitor

* Valid RESET remains with VCC as low as 1V

* 200ms Reset Pulse Width

* Independent Watchdog Timer (1.9sec) Timeout

* Voltage Monitor for Power-Fail or Low-Battery Warning

* With Manual reset input