Switched capacitor recirculating converter circuits
A converter circuit. In one aspect, the converter circuit includes an input terminal, a first output terminal and a second output terminal, and first, second, third and fourth capacitors coupled to a plurality of switches, where the plurality of switches are arranged to repetitively cycle the first, second, third and fourth capacitors between a first state and a second state to generate first and a second output voltages, where in the first state, the first and second capacitors are connected in parallel with each other and in series with a third capacitor to apply a first fraction of an input voltage at the first output terminal, and in the second state, the first and second capacitors are connected in series with each other and in parallel with the fourth capacitor to apply a second fraction of the input voltage at the second output terminal.
1. A circuit comprising:
a switched capacitor circuit comprising first, second, third and fourth capacitors coupled to a plurality of switches; and
a first output terminal, a second output terminal, a power input terminal and a ground coupled to the switched capacitor circuit;
wherein the switched capacitor circuit repetitively cycles between a first state and a second state;
wherein when in the first state, the first capacitor is coupled in parallel with the second capacitor, and the first and second capacitors are coupled between the ground and the first output terminal; and
wherein when in the second state, the first capacitor is coupled in series with the second capacitor, and the series connected first and second capacitors are coupled between the second output terminal and the ground.
2. The circuit of claim 1 , wherein when in the first and second states, the first output terminal is connected to the power input terminal via the third capacitor.
3. The circuit of claim 2 , wherein when in the first and second states, the second output terminal is connected to ground via the fourth capacitor.
4. The circuit of claim 3 , wherein the switched capacitor circuit is arranged to generate a first output voltage at the first output terminal and a second output voltage at the second output terminal.
5. The circuit of claim 4 , wherein the second output voltage is greater than the first output voltage.
6. The circuit of claim 4 , wherein the first output voltage is ⅓ of a voltage at the power input terminal.
7. The circuit of claim 4 , wherein the second output voltage is ⅔ of a voltage at the power input terminal.
8. The circuit of claim 4 , further comprising a first transistor coupled to a second transistor in a half-bridge configuration circuit, and a first driver circuit coupled to the first transistor and arranged to control a conductivity state of the first transistor, and a second driver circuit coupled to the second transistor and arranged to control a conductivity state of the second transistor.
9. The circuit of claim 8 , wherein the first driver circuit includes a first positive power supply terminal and a first negative power supply terminal, and the second driver circuit includes a second positive power supply terminal and a second negative power supply terminal.
10. The circuit of claim 9 , wherein the power input terminal is coupled to the first positive power supply terminal and the first output terminal is coupled to the first negative power supply terminal, and wherein the second output terminal is coupled to the second positive power supply terminal and the ground is coupled to the second negative power supply terminal.
11. The circuit of claim 10 , wherein the first transistor is coupled to the power input terminal and the second transistor is coupled to the ground.
12. A circuit comprising:
an input terminal, a first output terminal and a second output terminal; and
first, second, third and fourth capacitors coupled to a plurality of switches, the plurality of switches arranged to repetitively cycle the first, second, third and fourth capacitors between a first state and a second state to generate a first output voltage, in response to receiving an input voltage at the input terminal, at the first output terminal and a second output voltage at the second output terminal; and
wherein in the first state, the first and second capacitors are connected in parallel with each other and in series with a third capacitor to apply a first fraction of the input voltage at the first output terminal.
13. The circuit of claim 12 , wherein in the second state, the first and second capacitors are connected in series with each other and in parallel with the fourth capacitor to apply a second fraction of the input voltage at the second output terminal.
14. The circuit of claim 13 , wherein the first fraction is ⅓ of the input voltage.
15. The circuit of claim 13 , wherein the second fraction is ⅔ of the input voltage.
16. The circuit of claim 13 , further comprising a first transistor coupled to a second transistor in a half-bridge configuration circuit, and a first driver circuit coupled to the first transistor and arranged to control a conductivity state of the first transistor, and a second driver circuit coupled to the second transistor and arranged to control a conductivity state of the second transistor.
17. The circuit of claim 16 , wherein the first driver circuit includes a first positive power supply terminal and a first negative power supply terminal, and the second driver circuit includes a second positive power supply terminal and a second negative power supply terminal.
18. The circuit of claim 17 , wherein the input terminal is coupled to the first positive power supply terminal and the first output terminal is coupled to the first negative power supply terminal, and wherein the second output terminal is coupled to the second positive power supply terminal and a ground is coupled to the second negative power supply terminal.
19. The circuit of claim 18 , wherein the first transistor is coupled to the input terminal and the second transistor is coupled to the ground.
20. The circuit of claim 13 , wherein the second fraction is greater than the first fraction.