Patent ID: 9608509
Date: 2017-03-28
CPC Classifications: H02M

Claim:
1. A control circuit for controlling a switching converter, the switching converter having a first switch and an output terminal configured to provide an output voltage, the control circuit comprising: a voltage regulating circuit, configured to provide an auxiliary power supply voltage across a capacitor; a switching control circuit, configured to provide a pulse signal based on a reference signal and a feedback signal representative of the output voltage; a first logic circuit, coupled to the switching control circuit, and wherein the first logic circuit is configured to provide a switching control signal to a control terminal of the first switch based on a protection signal and the pulse signal; and a restart delay circuit, coupled to the voltage regulating circuit, wherein the restart delay circuit is configured to provide an enable signal based on the protection signal and the auxiliary power supply voltage, and wherein when the protection signal is in a first state, the enable signal is configured to disable the voltage regulating circuit and the switching control circuit until the auxiliary power supply voltage decreases to a first threshold; and wherein the restart delay circuit further comprising: an under-voltage detecting circuit, having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the voltage regulating circuit, and the second input terminal is configured to receive the first threshold, and the output terminal is configured to provide a reset signal based on comparing the auxiliary power supply voltage with the first threshold; and a flip-flop, having a set terminal, a reset terminal and an output terminal, wherein the set terminal is configured to receive the protection signal, the reset terminal is coupled to the output terminal of the under-voltage detecting circuit to receive the reset signal, and the output terminal is configured to provide the enable signal based on the protection signal and the reset signal.