Invention Grant
- Patent Title: Flyback converter with a variable frequency discontinuous mode and valley sensing
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Application No.: US17334745Application Date: 2021-05-30
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Publication No.: US11451154B2Publication Date: 2022-09-20
- Inventor: Kun-Yu Lin , Tzu-Chen Lin , Wei-Hsu Chang , Ta-Yung Yang
- Applicant: RICHTEK TECHNOLOGY CORPORATION
- Applicant Address: TW Hsinchu
- Assignee: RICHTEK TECHNOLOGY CORPORATION
- Current Assignee: RICHTEK TECHNOLOGY CORPORATION
- Current Assignee Address: TW Hsinchu
- Agency: Tung & Associates
- Priority: TW109139182 20201110
- Main IPC: H02M3/335
- IPC: H02M3/335 ; H02M1/38

Abstract:
A flyback power converter circuit includes: a power transformer, a primary side switch and a conversion control circuit. In a DCM, during a dead time, the conversion control circuit calculates an upper limit frequency corresponding to output current according to a frequency upper limit function, and obtains a frequency upper limit masking period according to a reciprocal of the upper limit frequency, wherein the frequency upper limit masking period is a period starting from when the primary side switch is turned ON. During an upper limit selection period, the conversion control circuit selects a valley among one or more valleys in a ringing signal related to a voltage across the primary side switch as an upper limit locked valley, so that the conversion control circuit once again turns ON the primary side switch at a beginning time point of the upper limit locked valley.
Public/Granted literature
- US20210376734A1 FLYBACK POWER CONVERTER CIRCUIT AND CONVERSION CONTROL CIRCUIT AND CONTROL METHOD THEREOF Public/Granted day:2021-12-02
Information query
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