At present,half bridge LLC resonant power supply mostly uses electrolytic capacitor to filter,aiming at the low life of electrolyte volatilization of electrolytic capacitor.In this design,CBB capacitor with high life is used to filter instead of electrolytic capacitor.However,CBB has low capacitance value and poor filtering effect,which leads to the problems of large voltage ripple and wide input voltage range.Therefore,STM32 is used as the main control chip in this design,which is solved by the combination of frequency conversion control(PFM) and variable pulse width control(PWM).It is verifi...