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, which for example, receives an input voltage through a terminal. The sampling component, for example, samples the input voltage and generates a sampled voltage. Additionally, the system includes an error amplifier which for example, processes information associated with the sampled voltage and a threshold voltage and generates a first output signal, and a first signal generator which for example, generates a second output signal and one or more third output signals. Moreover, the system includes a comparator which for example, receives the first output signal and the second output signal and generates a comparison signal, and a gate driver directly or indirectly coupled to the comparator. The gate driver, for example, generates 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 converter, the system comprising:
a sample-and-hold circuit located on a chip configured to receive an input voltage through a terminal, the sample-and-hold circuit being configured to sample the input voltage, hold the sampled input voltage, and generate a sampled-and-held voltage; an error amplifier configured to process information associated with the sampled-and- held 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 driver 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 the one or more third output signals and generate a compensation current flowing out of the chip through the terminal; wherein:
the 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 converter, the power converter including 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 during which the second output signal increases in magnitude; andthe compensation current decreases in magnitude in response to a second time period increasing, 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.