Method of operating isolated resonant converter with synchronous rectifier
AssigneeTexas Instruments Incorporated
InventorsRamkumar Sivakumar, Brent Alan McDonald, Yalong Li
Life of this patent
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Abstract
A method for operating a resonant converter in a burst mode includes determining the polarity of a transformer voltage across a secondary winding of a transformer. The method includes determining, from the polarity of the transformer voltage, on/off states of first and second transistors coupled to the secondary winding of the transformer. If the transformer voltage has a first polarity, the method includes commencing a burst period by alternately turning on/off high-side and low-side transistors electrically connected to a primary winding of the transformer.
Claims15
A method for operating a resonant converter in a burst mode, the method comprising:
- determining a polarity of a transformer voltage across a secondary winding of a transformer;
- determining, from the polarity of the transformer voltage, an on/off state of first and second transistors coupled to the secondary winding of the transformer;
- and
- commencing a burst period by alternately turning on/off a high-side transistor and a low-side transistor in response to the transformer voltage having a first polarity, wherein the high-side transistor and the low-side transistor are being coupled to a primary winding of the transformer;
- and
- holding the resonant converter in a burst interval by delaying a start of a first pulse of the burst period in response to the transformer voltage having a second polarity, wherein the high-side transistor and the low-side transistor are turned off during the burst period.
A method for operating a resonant converter in a burst mode, the method comprising:
- determining a first voltage that represents an output power delivered by the resonant converter;
- comparing the first voltage to a burst threshold voltage that represents a target output power;
- determining a polarity of a transformer voltage across a secondary winding of a transformer in response to the first voltage being less than the burst threshold voltage;
- determining, from the polarity of the transformer voltage, an on/off state of first and second transistors coupled to the secondary winding of the transformer;
- and
- commencing a burst period by alternately turning on/off a high-side transistor and a low-side transistor in response to the transformer voltage having a first polarity, wherein the high-side transistor and the low-side transistor are electrically connected to a primary winding of the transformer.
A method for operating a resonant converter in a burst mode, the method comprising:
- determining a first voltage that represents an output power delivered by the resonant converter;
- comparing the first voltage to a burst threshold voltage that represents a target output power;
- determining a polarity of a transformer voltage across a secondary winding of a transformer in response to the first voltage being less than the burst threshold voltage;
- commencing a burst period by alternately turning on/off a transistor electrically connected to a primary winding of the transformer in response to the transformer voltage having a first polarity;
- holding the resonant converter in a burst interval by delaying a start of a first pulse of the burst period in response to the transformer voltage having a second polarity;
- and
- holding the resonant converter in the burst interval in response to the first voltage being greater than the burst threshold voltage.
A method for operating a resonant converter in a burst mode, the method comprising:
- determining a first voltage that is represents an output power delivered by the resonant converter;
- comparing the first voltage to a burst threshold voltage that represents a target output power;
- determining a polarity of a transformer voltage across a secondary winding of a transformer in response to the first voltage being less than the burst threshold voltage;
- commencing a burst period by alternately turning on/off a high-side transistor and a low-side transistor in response to the transformer voltage having a first polarity, wherein the high-side transistor and the low-side transistor are electrically connected to a primary winding of the transformer;
- holding the resonant converter in a burst interval by delaying a start of a first pulse of the burst period in response to the transformer voltage having a second polarity;
- and
- holding the resonant converter in the burst interval in response to the first voltage being greater than the burst threshold voltage.
Dependencies are inferred from the claim text.