| 摘要 |
A fixed-on-time controller utilizing an adaptive saw signal for discontinuous mode PFC power conversion, the fixed-on-time controller comprising: an error amplifier, having a negative input end coupled to a feedback signal, a positive input end coupled to a reference voltage, and an output end for providing a threshold signal; an adaptive current source generator, used to generate an adaptive current source according to the threshold signal; a capacitor, charged by the adaptive current source, being used for carrying a saw signal; a switch, used to discharge the capacitor under the control of a reset signal; and a comparator, having a negative input end coupled to the threshold signal, a positive input end coupled to the saw signal, and an output end for providing a turn-off signal; and a fixed-on-time driver circuit, used to provide a driving signal and the reset signal according to the turn-off signal and a sensing signal.
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