| 摘要 |
PROBLEM TO BE SOLVED: To obtain high efficiency properties in the low voltage output of a synchronous rectifier, while keeping high efficiency of an E-class rectifier. SOLUTION: A driver circuit 150 is driven by the clock signal from an oscillator 151, synchronized with the input current from an AC power source 110. The clock signal is shifted to a phase, where the switching device 132 of an E-class synchronous rectifier 130 switches by means of a phase shifter 152. The shifted signals are counted by a counter 153, and divided pulses are generated. The divided pulses are outputted to a logical circuit 159 via a digital block 154. This logical circuit 159 generates or thins pulses as to desired cycle, based on the divided pulses from the digital block 154 and the selector signal outputted form an analog/digital converter 155. The logic circuit 159 outputs a switch drive signal, based on the output of the phase shifter 152 and a multiplexer 161, and drives the switching device 132 thereby realizing zero-voltage switching. COPYRIGHT: (C)2003,JPO
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