ILC1232

Impala Linear Corporation ILC1232 mP Supervisory Circuit General Description The ILC1232 is a multifunction circuit which monitors microprocessor activity, external reset and power supplies in microprocessor based systems. The circuit functions include a watchdog timer, power supply monitor, microprocessor reset, and manual pushbutton reset input. The power supply line 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 mP activity and will assert RST if no mP activity has occurred within the watchdog timeout period. The watchdog timeout period is selectable with nominal periods of 150, 600, or 1200 milliseconds. Features Power OK/Reset Time Delay, 250ms min. Watchdog Timer, 150ms, 600ms, or 1.2s typical Preci...