Systems and methods for load compensation with primary-side sensing and regulation for flyback power converters

摘要

System and method for regulating an output voltage of a power conversion system. The system includes a sampling component located on a chip configured to receive an input voltage through a terminal. The sampling component is configured to sample the input voltage and generate a sampled voltage. Additionally, the system includes an error amplifier configured to process information associated with the sampled voltage and a threshold voltage and generate a first output signal, and a first signal generator configured to generate a second output signal and one or more third output signals. Moreover, the system includes a comparator configured to receive the first output signal and the second output signal and generate a comparison signal, and a gate driver directly or indirectly coupled to the comparator and configured to generate a drive signal based on at least information associated with the comparison signal.

主权项

1. A system for regulating an output voltage of a power conversion system, the system comprising:
a sampling component located on a chip configured to receive an input voltage through a terminal, the sampling component being configured to sample the input voltage and generate a sampled voltage; an error amplifier configured to process information associated with the sampled voltage and a threshold voltage and generate a first output signal; a first signal generator configured to generate a second output signal and one or more third output signals; a comparator configured to receive the first output signal and the second output signal and generate a comparison signal; a gate driver directly or indirectly coupled to the comparator and configured to generate a drive signal based on at least information associated with the comparison signal; and a current generator configured to receive at least the one or more third output signals and generate a compensation current flowing out of the chip through the terminal; wherein:
the gate driver is further coupled to a first switch configured to receive the drive signal and affect a first current flowing through a primary winding coupled to a secondary winding;the secondary winding is associated with at least an output voltage of a power conversion system, the power conversion system including at least the primary winding, the secondary winding, and an auxiliary winding, the auxiliary winding being coupled to the secondary winding; andthe input voltage is associated with at least the auxiliary winding and depends on at least the output voltage and the compensation current; wherein:
the second output signal starts to increase from a first magnitude at a first time;the one or more third output signals represent a first time period since the first time during which the second output signal increases in magnitude; andthe compensation current decreases in magnitude if a second time period increases, the second time period starting from the first time and ending at a second time when the second output signal becomes equal to the first output signal in magnitude.