Systems and methods for constant current control with primary-side sensing and regulation in various operation modes

摘要

System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

主权项

1. A system for regulating a power converter, the system comprising:
a first signal processing component configured to receive at least a sensed signal and generate a first signal, the sensed signal being associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter; a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal; a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal; a signal generator configured to receive at least the comparison signal and generate a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to a switch, the switch being configured to affect the primary current flowing through the primary winding; wherein the drive signal is associated with at least one or more switching periods, each of the one or more switching periods including at least an on-time period for the switch and a demagnetization period for a demagnetization process; wherein for each of the one or more switching periods,
the first signal represents the demagnetization period multiplied by a sum of a first current magnitude and a second current magnitude, the first current magnitude representing the primary current at the beginning of the on-time period, the second current magnitude representing the primary current at the end of the on-time period; andthe second signal represents the switching period multiplied by a predetermined current magnitude; wherein:
the integrator component is further configured to integrate period-by-period differences between the first signal and the second signal for a plurality of switching periods; andthe third signal represents the integrated period-by-period differences, the integrated period-by-period differences being smaller than a predetermined threshold in magnitude.