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 a power converter, the system comprising:
a pulse-width-modulation generator configured to receive at least a first comparison signal associated with at least a feedback signal related to an output current of the power converter and generate a modulation signal based at least in part on 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 first current flowing through a primary winding of the power converter, the first current being associated with a peak magnitude for each modulation period corresponding to the modulation frequency; and a 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 detection component being further configured to receive 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 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; andin response to the one or more first conditions being satisfied, increase the modulation frequency and the peak magnitude related to the first current.