| 摘要 |
PROBLEM TO BE SOLVED: To provide an isolated flyback converter with a sleep mode for light load operation.SOLUTION: A method for operating a flyback converter comprises: sensing the output voltage using primary side sensing; turning on the first transistor; turning on the second transistor; detecting whether the output voltage has exceeded a predetermined regulated voltage by a first threshold; if the over-voltage condition is detected, disabling at least the first transistor; while in the sleep mode, detecting that the output voltage has dropped below the predetermined regulated voltage by a second threshold; turning the second transistor on and then off; detecting the pulse in the primary winding; and upon detecting the pulse in the primary winding, controlling the converter to come out of the sleep mode. |
