Fast Over-Voltage and Surge Detector

In this paper, a fast threshold-based over voltage (OV) detector which turns on during a surge event is introduced. It stays off in normal condition to avoid extra current consumption which is critical for low-power applications. A combination of diode-connected transistors with resistors will detect the pad voltages above a certain level. A fast comparator will be enabled when the pad voltage is higher than the certain level and compare it with an accurate reference voltage. Output of the comparator will trigger an over-voltage detected signal that will be used as surge/over voltage detector to turn off the switch and remove power from the rest of the chip. It is implemented in 0.14um high-voltage CMOS technology and protects the device side of the switch against any over voltage/surge condition on the connector side and makes the related pin stay compliant with IEC 61000-4-5 standard.