US Patent 7990672 Supervision circuit to detect very fast power supply drops

This invention is power supply protection for complex digital circuits employing an external high voltage supply and an internally generated low voltage core logic supply. Precision analog comparators distinguish between short circuit conditions on the internal supply at various ramp down rates including slow brown out decay. Control circuitry protects I/O circuits from exposure to high currents as a result of possible floating gate conditions in the output circuitry.