Method and apparatus for digital, closed-loop control of CrCM switch-mode power converters
AssigneeNexgen Power Systems, Inc.
InventorAnders Lind
Life of this patent
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Abstract
A method of setting a synchronous rectifier on-time value includes determining that a time interval has occurred, receiving a number of triangular current mode (TCM) pulses measured during the time interval, and determining a pulse comparison value equal to a number of switching period pulses during the time interval minus the number of TCM pulses during the time interval. The method also includes increasing the synchronous rectifier on-time if the pulse comparison value is greater than or equal to a threshold and decreasing the synchronous rectifier on-time if the pulse comparison value is less than the threshold.
Claims20
A method of setting a synchronous rectifier on-time value, the method comprising:
- determining that a time interval has occurred;
- receiving a number of triangular current mode (TCM) pulses measured during the time interval;
- determining a pulse comparison value equal to a number of switching period pulses during the time interval minus the number of TCM pulses during the time interval;
- increasing a synchronous rectifier on-time if the pulse comparison value is greater than or equal to a threshold;
- and
- decreasing the synchronous rectifier on-time if the pulse comparison value is less than the threshold.
A method for operating a power converter, the method comprising:
- comparing, during a first time period of a first AC half-cycle, a first voltage associated with an inductor current to a negative reference value;
- generating a first set of pulses corresponding to a number of times that the first voltage becomes less than or equal to the negative reference value;
- determining that a number of the first set of pulses is less than a number of switching periods during the first time period;
- and
- increasing a synchronous rectifier conduction time for a first switch;
- comparing, during a second time period of a second AC half-cycle, a second voltage associated with the inductor current to the negative reference value;
- generating a second set of pulses corresponding to a number of times that the second voltage becomes less than or equal to the negative reference value;
- determining that a number of the second set of pulses is equal to the number of switching periods during the first time period;
- and
- decreasing the synchronous rectifier conduction time for the first switch.
Dependencies are inferred from the claim text.