Method and apparatus for generating an adaptive switching frequency for operating power factor correction circuit
First Claim
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1. A method of operating a PFC (power factor correction) circuit having a main PFC FET and a boost inductor, the method comprising:
- determining an adaptive switching frequency of the PFC circuit related to a current of the boost inductor; and
operating the PFC circuit at a light load based on the adaptive switching frequency, wherein determining the adaptive switching frequency of the PFC circuit comprises determining a time that the current of the boost inductor resonates from a negative value to a zero value, and generating the adaptive switching frequency based on the determined time.
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Abstract
A method of operating a power factor correction (PFC) circuit and a corresponding power factor correction circuit include determining an adaptive switching frequency of the PFC circuit related to a current of the boost inductor of the PFC circuit, and operating the PFC circuit at a light load based on the adaptive switching frequency.
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Citations
17 Claims
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1. A method of operating a PFC (power factor correction) circuit having a main PFC FET and a boost inductor, the method comprising:
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determining an adaptive switching frequency of the PFC circuit related to a current of the boost inductor; and operating the PFC circuit at a light load based on the adaptive switching frequency, wherein determining the adaptive switching frequency of the PFC circuit comprises determining a time that the current of the boost inductor resonates from a negative value to a zero value, and generating the adaptive switching frequency based on the determined time. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a PFC (power factor correction) circuit having a main PFC FET and a boost inductor, the method comprising:
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determining if the PFC circuit is operating in a first mode or in another mode; if the PFC circuit is operating in the first mode, determining an adaptive switching frequency of the PFC circuit related to a current of the boost inductor; and operating the PFC circuit at a light load based on the adaptive switching frequency, wherein determining the adaptive switching frequency of the PFC circuit further comprises generating a Syn signal based on a time that the current of the boost inductor resonates from a negative value to a zero value, and turning on the main PFC FET based on the Syn signal. - View Dependent Claims (8, 9, 10, 11)
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12. A PFC (power factor correction) circuit having a main PFC FET and a boost inductor, comprising:
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a Syn signal generator that detects a current of the boost inductor; and a controller that determines an adaptive switching frequency based on the current of the boost inductor and controls operation of the PFC circuit at a light load based on the adaptive switching frequency, wherein the controller determines the adaptive switching frequency of the PFC circuit by determining a time that the current of the boost inductor resonates from a negative value to a zero value, and generates the adaptive switching frequency based on the determined time. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification