Switch circuit of DC/DC converter configured to conduct various modes for charging/discharging

• US 8,159,091 B2
• Filed: 01/22/2010
• Issued: 04/17/2012
• Est. Priority Date: 04/01/2009
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: Yeates, David Julian
• Primary Examiner(s): DeBeradinis, Robert L.
• Application Number:
  US12/692,273
• Publication Number:
  US 20100253154A1
• Time in Patent Office: 816 Days
• Field of Search: 307/110
• US Class Current: 307/110
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A DC/DC converter includes an input terminal for receiving an input voltage; an output terminal for providing an output voltage; a ground terminal for providing a reference voltage; a plurality of charge pump capacitors including at least a first charge pump capacitor, a second charge pump capacitor, and a third charge pump capacitor; and a switch circuit. The switch circuit includes a plurality of switches configured to allow the plurality of charge pump capacitors connected in a hybrid parallel-series arrangement between the input terminal and the ground terminal or between the input terminal and the output terminal by selectively conducting a specified portion of the switches.

Claims

1. A DC/DC converter, comprising:

an input terminal for receiving an input voltage;

an output terminal for providing an output voltage;

a ground terminal for providing a reference voltage;

a plurality of charge pump capacitors, comprising at least a first charge pump capacitor, a second charge pump capacitor, and a third charge pump capacitor; and

a switch circuit including a plurality of switches configured to allow the plurality of charge pump capacitors connected in a hybrid parallel-series arrangement between the input terminal and the ground terminal or between the input terminal and the output terminal by selectively conducting a specified portion of the switches.

2. The DC/DC converter according to claim 1, further comprising a controller for controlling a conductive pattern of the switches of the switch circuit so as to change the DC/DC converter between a charging phase that the plurality of charge pump capacitors are connected between the input terminal and the ground terminal and a discharge phase that the plurality of charge pump capacitors are connected between the input terminal and the output terminal, and establish one of a variety of modes including the hybrid parallel-series arrangement for use in the charging phase or the discharging phase.

3. The DC/DC converter according to claim 2, wherein the variety of modes includes an essential series arrangement of some or all of the plurality of charge pump capacitors.

4. The DC/DC converter according to claim 2, wherein the variety of modes includes an essential parallel arrangement of some or all of the plurality of charge pump capacitors.

5. The DC/DC converter according to claim 2, wherein the controller controls the configuration of the switches to be the same or different arrangements selected from the variety of modes in the charging phase and in the discharging phase.

6. The DC/DC converter according to claim 1, wherein the hybrid parallel-series arrangement includes a first sub-arrangement of at least two of the plurality of charge pump capacitors connected in a parallel arrangement and a second sub-arrangement of the other charge pump capacitors connected in series to the first sub-arrangement.

7. The DC/DC converter according to claim 1, wherein the hybrid parallel-series arrangement includes a third sub-arrangement of at least two of the plurality of charge pump capacitors connected in a series arrangement and a second sub-arrangement of the other charge pump capacitors connected in parallel to the first sub-arrangement.

8. The DC/DC converter according to claim 1, wherein the switch circuit comprises:

a first circuitry associated with the first charge pump capacitor, one electrode of the first charge pump capacitor being connectable via a first switch to the input voltage and via a second switch to the reference voltage and the other electrode of the first charge pump capacitor being connectable via a third switch to the input voltage and via a fourth switch to the output voltage;

a second circuitry associated with the second charge pump capacitor, one electrode of the second charge pump capacitor being connectable via a fifth switch to the input voltage and via a sixth switch to the reference voltage and the other electrode of the second charge pump capacitor being connectable via a seventh switch to the input voltage and via an eighth switch to the output voltage;

a third circuitry associated with the third charge pump capacitor, one electrode of the third charge pump capacitor being connectable via a ninth switch to the input voltage and via a tenth switch to the reference voltage and the other electrode of the third charge pump capacitor being connectable via an eleventh switch to the input voltage and via a twelfth switch to the output voltage;

a first further switch, via which the one electrode of the first charge pump capacitor associated with the first circuitry being connectable to the other electrode of the second charge pump capacitor associated with the second circuitry; and

a second further switch, via which the one electrode of the second charge pump capacitor associated with the second circuitry being connectable to the other electrode of the third charge pump capacitor associated with the third circuitry.

9. The DC/DC converter according to claim 8, wherein the switch circuit further comprises a third further switch, via which the one electrode of the first charge pump capacitor associated with the first circuitry further being connectable to the other electrode of the third charge pump capacitor associated with the third circuitry.

10. The DC/DC converter according to claim 8, wherein the switch circuit further comprises:

a fourth circuitry associated with a fourth charge pump capacitor, one electrode of the fourth charge pump capacitor being connectable via a thirteenth switch to the input voltage and via a fourteenth switch to the reference voltage and the other electrode of the fourth charge pump capacitor being connectable via a fifteenth switch to the input voltage and via a sixteenth switch to the output voltage; and

a fourth further switch, via which the one electrode of the third charge pump capacitor associated with the third circuitry being connectable to the other electrode of the fourth charge pump capacitor associated with the fourth circuitry.

11. The DC/DC converter according to claim 10, wherein the switch circuit further comprises a fifth further switch, via which the one electrode of the second charge pump capacitor associated with the second circuitry further being connectable to the other electrode of the fourth charge pump capacitor associated with the fourth circuitry.

12. The DC/DC converter according to claim 11, wherein the switch circuit further comprises a sixth further switch, via which the one electrode of the first charge pump capacitor associated with the first circuitry further being connectable to the other electrode of the fourth charge pump capacitor associated with the fourth circuitry.

13. The DC/DC converter according to claim 1, wherein all of the plurality of switches are MOSFET switches.

14. An apparatus comprising a DC/DC converter according to claim 1, a battery and a circuit arrangement, wherein the battery is arranged to provide a battery voltage as the input voltage to the DC/DC-converter, and the DC/DC converter is arranged to provide the circuit arrangement with the output voltage.

15. The apparatus according to claim 14, wherein the circuit arrangement is associated with at least a display device capable of displaying images on the display device.

16. The apparatus according to claim 14, wherein the circuit arrangement is associated with at least a light source capable of emitting light when driven by the circuit arrangement.

17. The apparatus according to claim 14, being selected from a group consisting of a mobile phone, digital camera, PDA (personal digital assistant), notebook computer, desktop computer, television, car display, global positioning system (GPS), avionics display and portable DVD player.

18. A switch circuit for use with a plurality of charge pump capacitors in a DC/DC converter, the DC/DC converter including at least a first charge pump capacitor, a second charge pump capacitor, and a third charge pump capacitor, an input terminal for receiving an input voltage, an output terminal for providing an output voltage, and a ground terminal for providing a reference voltage, and the switch circuit comprising:

a first circuitry associated with the first charge pump capacitor, one electrode of the first charge pump capacitor being connectable via a first switch to the input voltage and via a second switch to the reference voltage and the other electrode of the first charge pump capacitor being connectable via a third switch to the input voltage and via a fourth switch to the output voltage;

a second circuitry associated with the second charge pump capacitor, one electrode of the second charge pump capacitor being connectable via a fifth switch to the input voltage and via a sixth switch to the reference voltage and the other electrode of the second charge pump capacitor being connectable via a seventh switch to the input voltage and via an eighth switch to the output voltage;

a third circuitry associated with the third charge pump capacitor, one electrode of the third charge pump capacitor being connectable via a ninth switch to the input voltage and via a tenth switch to the reference voltage and the other electrode of the third charge pump capacitor being connectable via an eleventh switch to the input voltage and via a twelfth switch to the output voltage;

a first further switch, via which the one electrode of the first charge pump capacitor associated with the first circuitry being connectable to the other electrode of the second charge pump capacitor associated with the second circuitry;

a second further switch, via which the one electrode of the second charge pump capacitor associated with the second circuitry being connectable to the other electrode of the third charge pump capacitor associated with the third circuitry; and

a third further switch, via which the one electrode of the first charge pump capacitor associated with the first circuitry further being connectable to the other electrode of the third charge pump capacitor associated with the third circuitry.

19. The switch circuit according to claim 18 wherein the switch circuit selectively connects the plurality of charge pump capacitors by:

connecting the plurality of charge pump capacitors in a series arrangement of all charge pump capacitors in a first mode;

connecting the plurality of charge pump capacitors in a parallel arrangement of all charge pump capacitors in a second mode; and

connecting the plurality of charge pump capacitors in a first hybrid parallel-series arrangement in a third mode, the first hybrid parallel-series arrangement comprising a first sub-arrangement of at least two of the plurality of charge pump capacitors connected in a parallel arrangement and a second sub-arrangement of the other charge pump capacitors connected in series to the first sub-arrangement; and

wherein the switch circuit further selectively connects the plurality of charge pump capacitors between;

the input terminal for receiving the input voltage and the ground terminal for charging the plurality of charge pump capacitors; and

the input terminal for receiving the input voltage and the output terminal for providing the output voltage (Vout) from discharging the plurality of charge pump capacitors.