Deadtime automatic-optimization system for flyback power supply having primary-side feedback in ccm, control system and method for flyback power supply having primary-side feedback in ccm

Abstract

An automatic dead zone time optimization system in a primary-side regulation flyback power supply continuous conduction mode (CCM), including a closed loop formed by a control system, including a single output digital to analog converter (DAC) midpoint sampling module, a digital control module, a current detection module, a dead zone time calculation module and a pulse-width modulation (PWM) driving module, and a controlled synchronous rectification primary-side regulation flyback converter. A primary-side current is sampled using a DAC Sampling mechanism to calculate a secondary-side average current, so as to obtain a primary-side average current and a secondary-side average current, in the case of CCM. A secondary-side current is input into the dead zone time calculation module to obtain a reasonable dead zone time; and the PWM driving module is jointly controlled by a primary-side regulation loop and the obtained dead zone time.