CPC H02M 3/33507 (2013.01) [H02M 1/0032 (2021.05); H02M 3/158 (2013.01)] | 21 Claims |
1. A control circuit for a switched-mode power supply for driving a first switch in the switched-mode power supply to convert an input voltage into an output voltage, the control circuit comprising
an on-time control unit, which receives a first signal characterizing a switching frequency of the first switch and a second signal characterizing a current flowing through the first switch and responsively generates a signal indicative of a turn-off instant for the first switch,
wherein when a peak value of the current flowing through the first switch drops below a predefined value, the on-time control unit determines the turn-off instant for the first switch based on the first signal so that the switching frequency of the first switch is maintained at a target frequency.
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