Controller for high efficiency resonant switching converters
First Claim
Patent Images
1. A DC to DC flyback converter for supplying power from an input voltage source to one or more output terminals, comprising:
- a transformer which isolates the one or more output terminals from the input voltage source;
a first semiconductor switch that, when ON, electrically couples said transformer with the input voltage source;
a resonant capacitor;
a second semiconductor switch that, when ON, electrically couples said resonant capacitor with said transformer;
control circuitry for alternately turning said first and second switches ON and OFF, respectively, said first switch according to a first duty cycle and said second switch according to a second duty cycle, wherein said second duty cycle is such that said second switch is turned ON only so long as is required to discharge said resonant capacitor.
1 Assignment
0 Petitions
Accused Products
Abstract
Resonant DC to DC flyback converter topologies having one or more transformers and a primary side resonant subcircuit are optimally controlled by providing independently derived duty cycles for driving the main transformer and resonant semiconductor switches to prevent cross-conduction thereof and minimize reverse recovery losses.
301 Citations
18 Claims
-
1. A DC to DC flyback converter for supplying power from an input voltage source to one or more output terminals, comprising:
-
a transformer which isolates the one or more output terminals from the input voltage source; a first semiconductor switch that, when ON, electrically couples said transformer with the input voltage source; a resonant capacitor; a second semiconductor switch that, when ON, electrically couples said resonant capacitor with said transformer; control circuitry for alternately turning said first and second switches ON and OFF, respectively, said first switch according to a first duty cycle and said second switch according to a second duty cycle, wherein said second duty cycle is such that said second switch is turned ON only so long as is required to discharge said resonant capacitor. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A DC to DC flyback converter for supplying power from an input voltage source to one or more output terminals, comprising:
-
a transformer which isolates the one or more output terminals from the input voltage source; a first semiconductor switch that, when ON, electrically couples said transformer with the input voltage source; a resonant capacitor; a second semiconductor switch that, when ON, electrically couples said resonant capacitor with said transformer; control circuitry for alternately turning said first and second switches ON and OFF, respectively, said first switch according to a first duty cycle and said second switch according to a second duty cycle, said first and second duty cycles characterized in that a substantially constant time period transpires between each time said second switch is turned OFF and said first switch is turned ON, said time period being only so long as is required to prevent cross conduction of said first and second switches, said second duty cycle further characterized in that said second switch is turned ON only so long as is required to discharge said resonant capacitor following a transfer of energy across said transformer. - View Dependent Claims (7, 8, 9, 10, 11, 12)
-
-
13. A DC to DC power converter for supplying power derived from an input voltage source to an output voltage terminal, comprising:
-
a transformer which isolates the output voltage terminal from the input voltage source, said transformer having a primary winding, a flyback-secondary winding and a forward-secondary winding, respectively; a load-side inductor electrically coupled with said forward-secondary winding; a load-side storage capacitor electrically coupled with said flyback-secondary winding, said inductor and capacitor connected in parallel across said output voltage terminal; a first semiconductor switch that, when ON, electrically couples said primary winding with the input voltage source; a resonant capacitor; a second semiconductor switch that, when ON, electrically couples said resonant capacitor with said primary winding; and control circuitry for alternately turning said first and second switches ON and OFF, respectively, said first switch according to a first duty cycle and said second switch according to a second duty cycle, said first and second duty cycles characterized in that a substantially constant time period transpires between each time said second switch is turned OFF and said first switch is turned ON, said time period being only so long as is required to prevent cross conduction of said first and second switches, said second duty cycle further characterized in that said second switch is turned ON only so long as is required to discharge said resonant capacitor following a transfer of energy across said transformer. - View Dependent Claims (14, 15, 16)
-
-
17. A method for controlling a DC to DC flyback converter, said converter comprising a transformer, a first semiconductor switch operated according to a first duty cycle, a primary side resonant capacitor, and a second semiconductor switch operated according to a second duty cycle, respectively, wherein said first switch, when ON, electrically couples said transformer with an input voltage, and wherein said second switch, when ON, electrically couples said primary winding with said resonant capacitor, the method comprising the step of:
selecting said second duty cycle such that said second switch is turned ON only so long as is required to discharge said resonant capacitor following a transfer of energy across said transformer. - View Dependent Claims (18)
Specification