Active reduced voltage switching using a supplemental switch
AssigneePower Integrations, Inc.
InventorDavid Michael Hugh Matthews
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Abstract
A controller includes a primary controller and a secondary controller to control switching of a power switch and a supplemental switch, respectively, coupled to an energy transfer element, e.g. an energy transfer element of a power converter. A ZV drive circuit are coupled to generate a ZVS signal that enables a ZV switch to store energy in the energy transfer element. The energy stored in the energy transfer element is coupled to reduce a switch voltage across the power switch prior to a next ON section of the primary drive signal. The secondary drive signal is generated in response to the drive signal and the ZVS signal.
Claims18
A controller for a power converter, the power converter having an energy transfer element and a primary side capacitance, the controller comprising:
- a secondary controller comprising;
- a forward voltage detector circuit coupled to produce a zero voltage switch (ZVS) enable signal when the power converter is in a discontinuous conduction mode,
- a ZVS drive circuit coupled to receive the ZVS enable signal and in response to the ZVS enable signal produce a ZVS drive signal, and
- a supplemental switch coupled to a secondary winding of the energy transfer element to receive the ZVS drive signal, and in response to the ZVS drive signal store energy through a current in the energy transfer element, wherein the current enables discharge of the primary side capacitance;
- and
- a primary controller coupled to a primary winding of the energy transfer element, wherein following the discharge of the primary side capacitance the primary controller produces a primary drive signal to store energy in the energy transfer element.
Dependencies are inferred from the claim text.