Power supply protection circuit with surge suppression and method thereof

A power supply protection circuit with surge suppression for suppressing surges in an output voltage of a power converter during load transitions, wherein the power converter includes a high-side switch, a low-side switch, an inductor, and an output capacitor, a first end of the high-side switch receives an input voltage, a second end of the high-side switch is connected to a first end of the low-side switch, a first end of the inductor is connected to the second end of the high-side switch and the first end of the low-side switch, a second end of the inductor is connected to a first end of the output capacitor, the high-side switch and the low-side switch are respectively controlled by a control circuit, and the power supply protection circuit includes:

• a discharge circuit configured to discharge the output voltage based on a discharge signal;
• and
• a surge detection circuit connected to the discharge circuit, wherein the surge detection circuit determines whether the output voltage meets a discharge condition based on a control signal of the low-side switch and the output voltage;
• wherein, when the discharge condition is met, the surge detection circuit outputs the discharge signal to the discharge circuit, and when the discharge condition is not met, the surge detection circuit stops outputting the discharge signal to the discharge circuit;
• wherein the discharge condition is whether the output voltage is greater than a reference voltage, whether the control signal of the low-side switch is a conduction signal, and whether a conduction time of the low-side switch in a Nth cycle is greater than a conduction time of the low-side switch in a N−1th cycle.