Single inductor multiple-input multiple-output switching converter and method of use

• US 7,256,568 B2
• Filed: 05/11/2005
• Issued: 08/14/2007
• Est. Priority Date: 05/11/2004
• Status: Active Grant

• Current Assignee: Hong Kong University of Science and Technology
• Original Assignee: Hong Kong University of Science and Technology
• Inventors: Ki, Wing Hung, Tsui, Chi Ying, Lam, Yat Hei
• Primary Examiner(s): Nguyen; Matthew V.
• Application Number:
  US11/126,875
• Publication Number:
  US 20050264271A1
• Time in Patent Office: 825 Days
• Field of Search: 323/220, 323/222, 323/223, 323/225, 323/232, 323/267, 323/268, 323/271, 323/272, 307/18, 307/31, 307 36- 39, 307/52, 307/80, 307/85, 307/86
• US Class Current: 323/222
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A single inductor multiple-input multiple-output (SI-MIMO) switching converter time-multiplexes different input power sources through only one inductor to provide multiple regulated output voltages, which can be used to power up different blocks of a portable electronic device (or whatever else it is used for) and at the same time to charge up a rechargeable battery. Power multiplexing is achieved by input switches that are also the switching elements of the switching converter, thus eliminating an additional power multiplexer.

Claims

1. A voltage converter comprising:

an inductor having a first end and a second end;

a plurality of first switches, connected between the first end of the inductor and a plurality of first terminals;

a plurality of second switches, connected between the second end of the inductor and a plurality of second terminals;

a freewheel switch, coupled between the first and the second end of the inductor;

a first ground switch, coupled between one of the ends of said inductor and a reference voltage; and

a switch controller, coupled to drive on/off switching of said plurality of first switches, said plurality of second switches, said freewheel switch and said first ground switch, wherein the switch controller is arranged to connect a first one of the first terminals to a different one or more of the second terminals, through the inductor, at different times, and to connect a second one of the first terminals to a different one or more of the second terminals, through the inductor, at different times.

2. The voltage converter of claim 1, wherein the switch controller is arranged to:

close a first one of the second switches, connected to a first one of the second terminals, and while the first one of the second switches is closed;

close a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor; and

open the first one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals;

open the first ground switch, open the first one of the second switches and close a second one of the second switches, connected to a second one of the second terminals, and while the second one of the second switches is closed;

close the first one of the first switches, to store energy in the inductor; and

open the first one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals.

3. The voltage converter of claim 1, wherein the first ground switch is coupled between the first end of said inductor and a reference voltage, and wherein the switch controller is arranged to:

while a first one of the second switches, connected to a first one of the second terminals, is closed;

close a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor;

open the first one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals;

close a freewheel switch and open all other switches to hold energy in the inductor;

open the first ground switch and the freewheel switch and close a second one of the first switches, to store energy in the inductor;

open the second one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals; and

close a freewheel switch and open all other switches to hold energy in the inductor.

4. The voltage converter of claim 1, wherein a first one of the first switches is connected to a first one of the first terminals, a second one of the first switches is connected to a second one of the first terminals, and the switch controller is arranged to:

gate the first one of the first switches when and only when a switching phase begins and said first one of the first terminals is selected as a power source, said switching phase beginning a time period when said inductor stores energy, which is then transferred to one of said outputs;

gate the second one of the first switches when and only when a switching phase begins and said second one of the first terminals is selected as a power source, said switching phase beginning a time period when said inductor stores energy, which is then transferred to one of said outputs.

5. The voltage converter of claim 1, further comprising a second ground switch coupled between the other one of the ends of said inductor and a reference voltage.

6. The voltage converter of claim 5, wherein the first ground switch is connected to the first end of the inductor.

7. The voltage converter of claim 1, wherein the first terminals comprise input power terminals, the first switches comprise input switches, the second terminals comprise output power terminals, and the second switches comprise output switches.

8. The voltage converter of claim 7, wherein the input terminals provide unregulated voltage sources and the output terminals provide independently regulated voltages.

9. The voltage converter of claim 1, further comprising capacitors, connected between individual second terminals and a reference voltage.

10. The voltage converter of claim 1, wherein the reference voltage is ground.

11. The voltage converter of claim 1, wherein the individual first switches are bipolar transistors or MOSFETs.

12. The voltage converter of claim 1, wherein the individual second switches are bipolar transistors, MOSFETs or diodes.

13. The voltage converter of claim 1, wherein said first ground switch is selected from a group consisting of a bipolar transistor and a MOSFET.

14. The voltage converter of claim 1, further comprising diodes in series with the first switches.

15. The voltage converter of claim 1, further comprising diodes in series with the second switches.

16. The voltage converter of claim 1, further comprising a diode in series with the first ground switch.

17. The voltage converter of claim 1, further comprising at least one source of electrical potential, coupled between at least one of the first terminals and said reference voltage.

18. The voltage converter of claim 17, wherein the at least one source of electrical potential is between two of a first positive supply voltage, a second positive supply voltage, a ground, a first negative supply voltage and a second negative supply voltage.

19. The voltage converter of claim 2, wherein said switch controller comprises time sequencing logic that controls ON-OFF switching of said first and second second switches such that said first and second second switches are charged alternately on a pulse by pulse basis.

20. The voltage converter of claim 2, wherein said switch controller comprises input terminal selection logic that controls ON-OFF switching of said first and second first switches, such that first terminal selection is done by activating the corresponding switch.

21. The voltage converter of claim 1, wherein a plurality of the first and second terminals are both first and second terminals.

22. A voltage converter comprising:

an inductor having a first end and a second end;

a plurality of first switches, connected between the first end of the inductor and a plurality of first terminals;

at least one second switch, connected between the second end of the inductor and at least one second terminal;

a first ground switch, coupled between one of the ends of said inductor and a reference voltage; and

a switch controller, coupled to drive on/off switching of said plurality of first switches, said at least one second switch and said first ground switch, wherein the switch controller is arranged to connect different ones of the first terminals to the at least one second terminal, through the inductor, at different times.

23. A voltage converter as defined in claim 22, wherein the switch controller is arranged to:

while the at least one second switch, connected to the at least one second terminal, is closed;

close a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor;

open the first one of the first switches and close the first ground switch, to transfer energy from the inductor to the at least one second terminal;

open the first ground switch and close a second one of the first switches, to store energy in the inductor; and

open the second one of the first switches and close the first ground switch, to transfer energy from the inductor to the at least one second terminal.

24. A method of operating a voltage converter, wherein the converter comprises an inductor having a first end and a second end;

a plurality of first switches, connected between the first end of the inductor and a plurality of first terminals;

a plurality of second switches, connected between the second end of the inductor and a plurality of second terminals;

a first ground switch, coupled between one of the ends of said inductor and a reference voltage; and

a switch controller, coupled to drive on/off switching of said plurality of first switches;

the method comprising;

closing a first one of the second switches, connected to a first one of the second terminals, and while the first one of the second switches is closed;

closing a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor; and

opening the first one of the first switches and closing the first ground switch, to transfer energy from the inductor to the first one of the second terminals;

opening the first ground switch, opening the first one of the second switches and closing a second one of the second switches, connected to a second one of the second terminals, and while the second one of the second switches is closed;

closing the first one of the first switches, to store energy in the inductor; and

opening the first one of the first switches and closing the first ground switch, to transfer energy from the inductor to the first one of the second terminals.

25. A method of operating a voltage converter, wherein the converter comprises an inductor having a first end and a second end;

a plurality of first switches, connected between the first end of the inductor and a plurality of first terminals;

a plurality of second switches, connected between the second end of the inductor and a plurality of second terminals;

a first ground switch, coupled between one of the ends of said inductor and a reference voltage; and

a switch controller, coupled to drive on/off switching of said plurality of first switches;

the method comprising;

closing a first one of the second switches, connected to a first one of the second terminals, and while the first one of the second switches is closed;

closing a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor;

opening the first one of the first switches and closing the first ground switch, to transfer energy from the inductor to the first one of the second terminals;

opening the first ground switch and closing a second one of the first switches, to store energy in the inductor; and

opening the second one of the first switches and closing the first ground switch, to transfer energy from the inductor to the first one of the second terminals.

26. A voltage converter comprising:

an inductor having a first end and a second end;

a plurality of first switches, connected between the first end of the inductor and a plurality of first terminals;

a plurality of second switches, connected between the second end of the inductor and a plurality of second terminals;

a first ground switch for inductor discharge, coupled between one of the ends of said inductor and a reference voltage; and

a switch controller, coupled to drive on/off switching of said plurality of first switches, said plurality of second switches and said first ground switch, wherein the switch controller is arranged to connect a first one of the first terminals to a different one or more of the second terminals, through the inductor, at different times, and to connect a second one of the first terminals to a different one or more of the second terminals, through the inductor, at different times.

27. The voltage converter of claim 26, wherein the switch controller is arranged to:

while a first one of the second switches, connected to a first one of the second terminals, is closed;

close a first one of the first switches, connected to a first one of the first terminals, to store energy in the inductor;

open the first one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals;

open the first ground switch and close a second one of the first switches, to store energy in the inductor; and

open the second one of the first switches and close the first ground switch, to transfer energy from the inductor to the first one of the second terminals.