Apparatus for improving stability and dynamic response of semi-bridge convertor

Abstract

The system and the method modules the error signal output by the feedback or the ramp signal into the various signals dependent on the voltage at the two ends of the blocking capacitor. The said signals are supplied to the PWM controller, making the converter stable. The modulation eliminates the influence of the resonant circuit formed by the primkary inductance and the blocking capacitor in theadjustment loop of the output voltage. Further, the load cycle of the power switch can be adjusted so as to keep the output voltage not interfered by the various voltages on the blocking capacitor. Thus, the variety of the voltage adjustment feedback loop caused by the internal compensating loop only responds to the inductance-capacitance filter. The quadravalent transmission function exhibits the second-order characteristic.