Study on the digitally controlled system of ZCS-QRC synchronous buck converter

This paper analyses the basic characteristic of digitally controlled ZCS-QRC synchronous buck converter, calculates the accurate value of on time, off time and dead times of switching MOSFETs, and puts forward an averaged switch model of the converter. In the digitally controlled system, the algorithm of online adaptive tuning digital PID regulator is used to obtain good dynamic performances. The dead times are estimated by online Dead Time Optimizer, which guarantees the power switches working at the conditions of zero currents or zero voltages and high efficiency of the converter. The converter has lower EMI and higher precision of averaged switch model, and has very good convert efficiency under the condition of the load current is not very low. It will be helpful for the design and implementation of the digital control system with the precise averaged switch model.