Systems and methods for flyback power converters with switching frequency and peak current adjustments based on changes in feedback signals

摘要

System and method for regulating a power converter. The system includes a first comparator configured to receive a first input signal and a second input signal and generate a first comparison signal based on at least information associated with the first input signal and the second input signal, a pulse-width-modulation generator configured to receive at least the first comparison signal and generate a modulation signal based on at least information associated with the first comparison signal, a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter, and a voltage-change-rate detection component configured to sample the feedback signal to generate a first sampled signal for a first modulation period and to sample the feedback signal to generate a second sampled signal for a second modulation period.

主权项

1. A system for regulating a power converter, the system comprising:
a first comparator configured to receive a first input signal and a second input signal and generate a first comparison signal based on at least information associated with the first input signal and the second input signal, the first input signal being associated with at least a feedback signal related to an output current of the power converter; a pulse-width-modulation generator configured to receive at least the first comparison signal and generate a modulation signal based on at least information associated with the first comparison signal, the modulation signal being associated with a modulation frequency; a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter, the primary current being associated with a peak magnitude for each modulation period corresponding to the modulation frequency; and a voltage-change-rate detection component configured to sample the feedback signal to generate a first sampled signal for a first modulation period and to sample the feedback signal to generate a second sampled signal for a second modulation period, the voltage-change-rate detection component being further configured to compare the first sampled signal and the second sampled signal in magnitude, the second modulation period being after the first modulation period; wherein the system for regulating the power converter is further configured to:
determine whether the first sampled signal subtracted by the second sampled signal satisfies one or more first conditions; andif the one or more first conditions are satisfied, increase the modulation frequency and the peak magnitude related to the primary current.