TC1232

TC1232 Microprocessor Monitor Features: Precision Voltage Monitor: - Adjustable +4.5V or +4.75V Reset Pulse Width – 250 ms minimum No External Components Adjustable Watchdog Timer: - 150 ms, 600 ms or 1.2s Operating Voltage 4.0V to 5.5V Debounced Manual Reset Input for External Override Block Diagram VCC Tolerance Select TOL (5% or 10%) + + + VR–EF – RST RST PB RST TD Debounce Watchdog Timebase Select Reset Generator Watchdog Timer ST General Description: The TC1232 is a fully-integrated processor supervisor that provides three important functions to safeguard processor sanity: precision power on/off Reset control, Watchdog Timer and external Reset override. On power-up, the TC1232 holds the processor in the Reset state for a minimum of 250 ms after VCC is within tolerance to ensure a stable system start-up. Microprocessor sanity is monitored by the on-board watchdog circuit. The microprocessor must provide a periodic low-going signal on the ST input. Should the processor fail to supply this signal within the selected time-out period (150 ms, 600 ms or 1200 ms), an outof-control processor is indicated and the TC1232 issues a processor Reset as a result. The outputs of the TC1232 are immediately driven active when the PB input is brought low by an external push button switch or other electronic signal. When connected to a push button switch, the TC1232 provides contact debounce. The TC1232 is packaged in a space-saving 8-Pin PDIP or SOIC package, a 16-P...