Time division multiplexing a DC-to-DC voltage converter

• US 8,247,999 B2
• Filed: 01/22/2008
• Issued: 08/21/2012
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Chen, Gang, Ryf, Roland, Duque, David A
• Primary Examiner(s): Le, Tung X
• Application Number:
  US12/009,851
• Publication Number:
  US 20090184659A1
• Time in Patent Office: 1,673 Days
• Field of Search: 315/185.R, 315/224, 315/291, 315/294, 315307-308, 323/207, 323/282, 323/315, 363/21.04, 363/21.12, 363/159
• US Class Current: 315/307
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

An apparatus includes a DC-to-DC voltage converter. The DC-to-DC voltage converter has a plurality of pairs of outputs and is configured to apply voltages across the pairs of outputs in a time division multiplexed manner.

Claims

1. An apparatus for driving a plurality of electronic loads, comprising:

a DC-to-DC voltage converter having a variable voltage output; and

a controller, the controller being configured to;

select one or more of the plurality of electronic loads and a corresponding output voltage level of the variable voltage output; and

apply a plurality of voltage levels from the variable voltage output across the plurality of electronic loads in accordance with the correspondence and a time division multiplexed scheme;

wherein the correspondence is established prior to the selection, and

wherein the selection of one or more of the plurality of electronic loads is done by effecting a shunt across the unselected one or more of the plurality of electronic loads.

2. The apparatus of claim 1, wherein the shunt is realizable using a plurality of shunt circuit paths, each shunt circuit path connecting between the outputs of a corresponding one of the electronic loads and having a switch there along.

3. The apparatus of claim 2, wherein the shunt circuit paths are electrically connected in series.

4. The apparatus of claim 1, wherein the variable voltage output further comprises circuit paths connected in parallel, each circuit path having the outputs of a corresponding one of the electronic loads there along and having a controllable switch there along.

5. The apparatus of claim 1, wherein the electronic loads comprise a first load operable at a first voltage and a second load operable at a different second voltage.

6. The apparatus of claim 5, wherein some of the electronic loads are light emitting diodes, each light source being configured to emit light of a different color.

7. The apparatus of claim 1, wherein the controller is further configured to shunt all of the plurality of electronic loads during certain times according to the time division multiplexed scheme.

8. An apparatus for driving a plurality of electronic loads, comprising:

a DC-to-DC voltage converter having a variable voltage output, the plurality of electronic loads being connected to share the DC-to-DC voltage converter over a plurality of circuit paths;

a controller, the controller being configured to;

select one or more of the plurality of electronic loads and a corresponding output voltage level of the variable voltage output;

apply a plurality of voltage levels from the variable voltage output across the plurality of electronic loads in accordance with the correspondence and a time division multiplexed scheme; and

effect a shunt across all of the plurality of electronic loads during certain times according to the time division multiplexed scheme;

wherein the correspondence is established prior to the selection;

wherein the loads are either connected across corresponding ones of the circuit paths or are part of corresponding ones of the circuit paths; and

wherein each path includes a switch there along and the controller is connected to operate the switches.

9. The apparatus of claim 8, wherein the controller is configured to open only one of the switches at a time during driving of the loads.

10. The apparatus of claim 8, wherein each circuit path is a shunt path for the corresponding one of the electronic loads, and the circuit paths are electrically connected in series.

11. The apparatus of claim 8, wherein the circuit paths are electrically connected in parallel and the loads are part of corresponding ones of the circuit paths.

12. The apparatus of claim 8, wherein the DC-to-DC voltage converter is one of a boost DC-to-DC voltage converter, a buck DC-to-DC voltage converter, a buck-boost DC-to-DC voltage converter, and a CUK DC-to-DC voltage converter.

13. The apparatus of claim 8, wherein the electronic loads comprise a first load operable at a first voltage and a second load operable at a different second voltage.

14. The apparatus of claim 8, wherein the DC-to-DC voltage converter is configured to apply a first voltage across a first of the loads and to apply a different second voltage across a second of the loads.

15. A method of driving a plurality of electronic loads, comprising:

selecting, by a controller, one or more of the plurality of electronic loads and a corresponding output voltage level of a DC-to-DC voltage converter having a variable voltage output; and

operating, by the DC-to-DC voltage converter in combination with the controller, a plurality of voltage levels from the variable voltage output across the plurality of electronic loads in accordance with the correspondence and a time division multiplexed scheme;

wherein the correspondence is established prior to the selection, and

wherein the selecting of one or more of the plurality of electronic loads is done by effecting a shunt across the unselected one or more of the plurality of electronic loads.

16. The method of claim 15, wherein the operating includes having the DC-to-DC voltage converter apply a first voltage across one of the electronic components and a different second voltage across another of the electronic components.

17. The method of claim 15, wherein the operating includes simultaneously closing a circuit path with one of the electronic components and opening one or more circuit paths with any other of electronic components when the DC-to-DC voltage converter is applying a voltage to the one of the electronic components, the circuit paths being connected in parallel.

18. The method of claim 15, further comprising:

effecting a shunt across all of the plurality of electronic components during certain times according to the time division multiplexed scheme;

then, discharging a capacitor during the certain times; and

then, repeating the operating step;

wherein charges on the capacitor drive the electronic components.