Ground fault detection circuit detecting whether a switching regulator's power output node is grounded

摘要

A switching regulator includes a ground fault detection circuit including: a p channel MOS transistor, a resistor and a diode together allowing a high frequency current to be supplied to a power output node; an inverter outputting a signal of the high level when the output node's potential exceeds a predetermined potential; and a D-type flip-flop set in response to the inverter outputting a signal of the high level to set an activation signal phiE high to activate a control circuit. When the power output node is grounded the control circuit is not activated and no overcurrent flows.