用于同步整流的周期性变结构波形整形理论

为了解决某些DC/DC变换器由于存在同步整流驱动死区而使变换效率低下的问题，提出了周期性变结构整形理论. 利用辅助的二极管和开关管对同步整流驱动电路结构进行切换，使之在一个周期内工作于不同的基本变换电路之间，从 而得到理想的同步整流驱动波形.利用周期性变结构整形理论完整地解释了一种现有的电荷自维持电路，并且构造出了一 系列新颖的周期性变结构整形电路.对一个36~75 V输入，5 V/10 A输出，采用周期性变结构整形电路的样机进行了实验 ，结果表明由上述理论所构造出的电路可以消除同步整流的驱动死区，提高变换效率.

Theory of waveform modification with periodical circuit structure adjustment method applicable to synchronous rectifier

In order to solve the dead time problem of synchronous rectifier that decreases the conversion efficiency,which occurs in some DC/DC converters,the theory of waveform modification with periodical circuit structure adjustment method applicable to synchronous rectifier was proposed.Synchronous rectifier operates at various basic regulation circuits among one duty cycle by using auxiliary diodes and switches,and then perfect driving waveforms for synchronous rectifier were obtained.By utilizing the proposed theory,the existing charge retention driving circuit was explained perfectly,furthermore a series of novel periodical structure adjustment circuits were constructed.An experimental prototype of waveform modification with periodical circuit structure adjustment method,which was 36~75 V input,5 V/10 A output,was fabricated.The experimental results show that circuits constructed by the theory can eliminate the dead time of synchronous rectifier and improve the conversion efficiency.