MIC1232

The MIC1232 is a multifunction circuit which monitors microprocessor activity, external reset and power supplies in microprocessor based systems. The MIC1232 functions include a watchdog timer, power supply monitor, microprocessor reset, and manual pushbutton reset input.

The power supply line of MIC1232 is monitored with a comparator and an internal voltage reference. RST is forced low when an out-of-tolerance condition exists and remains asserted for at least 250ms after VCC rises above the threshold voltage (4.5V or 4.75V). The RST pin will remain logic low with VCC as low as 1.4V.

The Watchdog input (ST) monitors P activity and will assert RST if no P activity has occurred within the watchdog timeout period. The watchdog timeout period of MIC1232 is selectable with nominal periods of 150, 600, or 1200 milliseconds.