Patent ID: 8680837

Claim:
A driver for driving a driving element, comprising: a signal source, for providing a square signal; a first modulation circuit, for providing on-pulses and off-pulses according to edges of the square signal; a transformer, coupled to the first modulation circuit for coupling output signals of the first modulation circuit to a secondary winding of the transformer to form coupled signals; a second modulation circuit, coupled to the second winding of the transformer for providing first operating pulses according to coupled on-pulses of the coupled signals, and providing second operating pulses according to coupled off-pulses of the coupled signals; a unidirectional on device, coupled between a first node of the secondary winding of the transformer and a control node of the driving element; and a switch device, having a control node coupled to the second modulation circuit, a first node coupled to the control node of the driving element and a second node coupled to a second node of the secondary winding of the transformer, wherein the switch device is turned off according to the first operating pulses and is turned on according to the second operating pulses, wherein when the switch device is turned off, coupled on-pulses charge an equivalent capacitor of the driving element to a first driving potential to turn on the driving element, and when the switch device is turned off, the equivalent capacitor discharges to a second driving potential to turn off the driving element, and wherein the width of the on-pulses is less than 1000 ns; wherein the on-pulses and the off-pulses generate an excitation current at a primary winding of the transformer, and the first modulation circuit generates one or more recovery pluses to balance the excitation current according to the on-pulses and the off-pulses.