Synchronous Rectifier Type Series Resonant Converter for Operating in Intermittence Mode

Abstract

Disclosed is a synchronous rectifier type SRC for operating in an intermittence mode, which includes: an input power for supplying the input DC voltage; an input-side switching unit for switching four input-side switching devices to convert the input DC voltage to AC voltage, the input-side switching unit being connected to the input power, an LC resonance circuit for storing energy in a resonance inductor and a resonance capacitor by means of LC resonance, and outputting resonance voltage, the LC resonance circuit being connected to the input-side switching unit; a transformer with a primary winding and a secondary winding for converting the resonance voltage to voltage of a predetermined level according to a turn ratio to generate secondary voltage, and transferring the secondary voltage through the secondary winding, the primary winding being connected to the LC resonance circuit; an output-side switching unit for switching four output-side switching devices to convert the secondary voltage to the output DC voltage, the output-side switching unit being connected to the secondary winding of the transformer; and a gate driving circuit for detecting a polarity of secondary current flowing in the secondary winding, generating dead time, generating driving signals for driving the output-side switching device of the output-side switching unit according to the polarity, and then controlling turn-on or turn-off of the output-side switching devices, the gate driving circuit being connected to both the secondary winding of the transformer and the output-side switching unit. According to the synchronous rectifier type SRC, a no-load characteristic can be controlled with an easy scheme and a simple construction. In addition, a simple resistor is added, and thus dead time can be generated. Consequently, it is possible to simply reduce switching loss that may occur in zero voltage switching.

Dependencies are inferred from the claim text.