CPC H02M 3/33523 (2013.01) [H02M 1/0025 (2021.05)] | 18 Claims |
17. A method for controlling a switching mode power supply, comprising:
sampling and holding an auxiliary winding feedback voltage of the switching mode power supply to obtain an auxiliary winding sample hold voltage;
sampling and holding the auxiliary winding feedback voltage at an inflection point time to obtain an auxiliary winding inflection point voltage when the switching mode power supply operates in DCM or CRM;
generating a secondary rectifier forward voltage signal based on the auxiliary winding sample hold voltage and the auxiliary winding inflection point voltage before the switching mode power supply operates in CCM;
providing a correction voltage based on the secondary rectifier forward voltage signal when the switching power supply operates in CCM;
generating an error amplifier signal based on the correction voltage;
adjusting an output power of the switching mode power supply based on the error amplifier signal;
wherein the correction voltage is an auxiliary winding correction voltage provided further based on the auxiliary winding sample hold voltage;
wherein when the switching mode power supply operates in CCM, the error amplifier signal is generated based on the auxiliary winding correction voltage and a reference voltage; and
wherein when the switching mode power supply operates in DCM or CRM, the error amplifier signal is generated based on the auxiliary winding inflection point voltage and the reference voltage.
|