Resonant converter with negative current feedback
A programmable, high efficiency resonant converter includes a resonant cell including a first capacitor and a first inductor, the resonant cell having a voltage output VOUT coupled to the first capacitor with a first switch and a first feedback input coupled to the first inductor; and a hard switching cell including a second capacitor and a second inductor, the hard switching cell having a second feedback input coupled to the second capacitor and a voltage output VX coupled to the second capacitor and to the first feedback input of the resonant cell, whereby a negative current is applied to the resonant cell.
1. A programmable, high efficiency resonant converter comprising:
a voltage output VOUT;
a resonant cell having a feedback input; and
a hard switching cell having a feedback input coupled to the voltage output VOUT and a voltage output VX coupled to the feedback input of the resonant cell;
wherein the resonant cell includes a series connection of a capacitor and an inductor, wherein the voltage output VOUT is coupled to the capacitor by a first switch and the feedback input is coupled to the first inductor by a second switch.
2. A programmable, high efficiency resonant converter as recited in claim 1 wherein the hard switching cell is configured as a Boost converter having a gain K.
3. A programmable, high efficiency resonant converter as recited in claim 1 , further comprising a control circuit coupled to the hard switching cell to control a gain of the hard switching cell.
4. A programmable, high efficiency resonant converter as recited in claim 1 , further comprising a control circuit control that provides voltage regulation for the hard switching cell.
5. A programmable, high efficiency resonant converter as recited in claim 1 , further comprising a control circuit including at least one operational amplifier (op amp) to continuously modulate a conversion ratio of the hard switching cell.
6. A programmable, high efficiency resonant converter as recited in claim 1 wherein the resonant cell has an input node VIN and an output node VL, and further comprising a Buck converter coupled between the input node VIN and the output node VL.
7. A programmable, high efficiency resonant converter as recited in claim 4 wherein the hard switching cell is configured as a Boost converter having a gain K.
8. A programmable, high efficiency resonant converter as recited in claim 2 wherein the Boost converter includes an inductor coupled to a capacitor and to the voltage output VX with a switch and wherein the voltage output VOUT is coupled to the inductor, whereby a negative current is applied to the resonant cell.
9. A programmable, high efficiency resonant converter comprising:
a voltage output VOUT;
a resonant cell having a feedback input including a first winding of a transformer;
a hard switching cell having a feedback input coupled to the voltage output VOUT and a voltage output VX coupled to the feedback input of the resonant cell; and
a rectifier including a second winding of the transformer coupling the voltage output VX to the feedback input of the resonant cell;
wherein the resonant cell includes the series connection of a first capacitor, the first winding of the transformer, and a second capacitor, wherein the first capacitor is coupled to the voltage output VOUT and the second capacitor is coupled to ground.
10. A programmable, high efficiency resonant converter as recited in claim 9 wherein the Boost converter includes an inductor coupled to a capacitor and to the voltage output VX with a switch and wherein the voltage output VOUT is coupled to the inductor, whereby a negative current is applied to the resonant cell.
11. A programmable, high efficiency resonant converter as recited in claim 9 further comprising a control circuit coupled to the hard switching cell to control a gain of the hard switching cell.
12. A programmable, high efficiency resonant converter as recited in claim 9 further comprising a control circuit control that provides voltage regulation for the hard switching cell.
13. A programmable, high efficiency resonant converter as recited in claim 9 further comprising a control circuit including at least one operational amplifier (op amp) to continuously modulate a conversion ratio of the hard switching cell.
14. A programmable, high efficiency resonant converter as recited in claim 9 wherein the resonant cell has an input node VIN and an output node VL, and further comprising a Buck converter coupled between the input node VIN and the output node VL.
15. A multistage resonant converter system comprising:
a voltage output VOUT;
a plurality of stages, each of which include
(a) a resonant cell having a feedback input;
(b) a hard switching cell having a feedback input coupled to the voltage output VOUT and a voltage output VX coupled to the feedback input of the resonant cell; and
(c) a series connection of a capacitor and a switch coupling a line connecting adjacent stages to one of VOUT and ground;
wherein the resonant cell includes a series connection of a capacitor and an inductor, wherein the voltage output VOUT is coupled to the capacitor by a first switch and the feedback input is coupled to the first inductor by a second switch.
16. A multistage resonant converter system as recited in claim 15 wherein the hard switching cell is configured as a Boost converter having a gain K.
17. A multistage resonant converter system as recited in claim 16 wherein the Boost converter includes an inductor coupled to a capacitor and to the voltage output VX with a switch and wherein the voltage output VOUT is coupled to the inductor, whereby a negative current is applied to the resonant cell.
18. A multistage resonant converter system comprising:
a voltage output VOUT;
a plurality of stages, each of which include
(a) a resonant cell having a feedback input;
(b) a hard switching cell having a feedback input coupled to the voltage output VOUT and a voltage output VX coupled to the feedback input of the resonant cell; and
(c) a series connection of a capacitor and a switch coupling a line connecting adjacent stages to one of VOUT and ground;
wherein the feedback input of the resonant cell includes a first winding of a transformer, and further comprising a rectifier includes a second winding of the transformer, wherein the rectifier couples the voltage output VX to the feedback input of the resonant cell; and
wherein the resonant cell includes the series connection of a first capacitor, the first winding of the transformer, and a second capacitor, wherein the first capacitor is coupled to the voltage output VOUT and the second capacitor is coupled to ground.
19. A method for providing a programmable, high efficiency resonant converter comprising:
resonating a current on a resonating line of a resonant cell including a series connection of a capacitor and an inductor;
providing a negative feedback current with a Boost converter coupled to an output voltage VOUT; and
coupling the output voltage VOUT to the capacitor by a first switch and coupling the negative feedback current to the inductor by a second switch.
20. A method for providing a programmable, high efficiency resonant converter as recited in claim 19 further comprising controlling a gain of the Boost converter.