Patent ID: 8860471

Claim:
An isolated gate driver, comprising: a driving control circuit, configured to generate a driving pulse-width-modulation (PWM) signal for driving a power switch tube; an isolated transformer, having a primary winding and a secondary winding; an anti-circuit, connected between the driving control circuit and the primary winding of the isolated transformer, the anti-circuit comprising a first diode and a capacitor which is clamped to a forward bias voltage of the first diode, and configured to suppress a variation of an induced voltage in the secondary winding of the isolated transformer when a duty cycle of the driving PWM signal is sharply decreased, wherein the first diode and the capacitor are connected in parallel; and a secondary processing circuit, connected in parallel with the secondary winding of the isolated transformer, configured to perform a voltage clamping action on a gate-source voltage of the power switch tube when the duty cycle of the driving PWM signal is sharply decreased.