DRIVE COMPENSATING CIRCUIT FOR SYNCHRONOUS RECTIFIER AND METHOD FOR ACTUATING THE SAME

摘要

PROBLEM TO BE SOLVED: To improve the efficiency of a synchronous rectifier by reducing the quantity of electric charges transmitted to the control terminals of rectifier switches, by limiting the voltage fluctuation of first and second drive signals by controlling first and second capacitive electric charges in first and second rectifier switches by means of first and second clamps. SOLUTION: A synchronous rectifier 130 is provided with first and second rectifier switches Q1 and Q2. A drive compensating circuit 140 improves the efficiency of the rectifier 130 by adjusting the quantity of electric charges transferred to the control terminals of the switches Q1 and Q2. In addition, a drive winding 150 and a drive compensating capacitor 155 provided in the circuit 140 generate first and second drive signals and send the signals to the first and second control terminals of the switches Q1 and Q2. First and second clamps 160 and 165 control the voltage fluctuation of the first and second drive signals by adjusting the electric charges of first and second input capacitors C1 and C2.