Power converter with capacitive energy transfer and fast dynamic response

• US 9,667,139 B2
• Filed: 05/11/2015
• Issued: 05/30/2017
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Giuliano, David M., Pilawa-Podgurski, Robert C. N., Perreault, David J.
• Primary Examiner(s): Pham, Emily P
• Application Number:
  US14/708,903
• Publication Number:
  US 20150280553A1
• Time in Patent Office: 750 Days
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A converter circuit and related technique for providing high power density power conversion includes a reconfigurable switched capacitor transformation stage coupled to a magnetic converter (or regulation) stage. The circuits and techniques achieve high performance over a wide input voltage range or a wide output voltage range. The converter can be used, for example, to power logic devices in portable battery operated devices.

Claims

1. A converter circuit comprising:

a switched capacitor transformation stage having a transformation stage input port and a transformation stage output port, said switched capacitor transformation stage comprising one or more switches and one or more capacitors and said switched capacitor transformation stage configured to accept an input voltage at the transformation stage input port and provide an intermediate output voltage at the transformation stage output port;

an auxiliary converter stage having an input coupled to said switched capacitor transformation stage, said auxiliary converter stage comprising one or more switches and one or more magnetic energy storage components configured to recover energy normally dissipated in capacitors of said switched capacitor transformation stage via said one or more magnetic energy storage components.

2. A converter circuit comprising:

a switched capacitor transformation stage having an input port and an output port, the switched capacitor transformation stage comprising one or more switches and one or more capacitors, the switched capacitor transformation stage configured to accept an input voltage at the input port and provide an intermediate output voltage at the output port;

an auxiliary converter stage having an input coupled to the switched capacitor transformation stage, the auxiliary converter stage comprising a plurality of switches, a plurality of capacitors and one or more magnetic energy storage components configured to recover energy normally dissipated in the switched capacitor transformation stage; and

a switching converter regulation stage having an output port and an input port coupled to the switched capacitor transformation stage output port to accept the intermediate voltage, the switching converter regulation stage configured to generate an output voltage of the converter circuit at the switching converter regulation stage output port.

3. The converter circuit of claim 2, further comprising:

a controller configured to provide one or more control signals to each of the switched capacitor transformation stage, the auxiliary converter stage and the switching converter regulation stage.

4. The converter circuit of claim 3, wherein the controller is configured to cause the switched capacitor transformation stage to operate at a first frequency, cause the switching converter regulation stage to operate at a second frequency, and cause the auxiliary converter stage to operate at a third frequency, wherein the first frequency is less than the second and third frequencies.

5. A voltage regulator comprising:

a first stage comprising a magnetic storage element, wherein the first stage is configured to receive the first voltage signal at a first terminal of the magnetic storage element and to provide an intermediate voltage signal at a second terminal of the magnetic storage element based, at least in part, on the first voltage signal;

a second stage comprising a plurality of input terminals and an output terminal, wherein the second stage is configured to receive, at one of the plurality of input terminals, the intermediate voltage signal from the second terminal of the magnetic storage element for a portion of a time period, and to provide the second voltage signal at the output terminal based, at least in part, on the received intermediate voltage signal; and

a controller configured to provide one or more control signals to each of the first stage and the second stage,

wherein the controller is configured to cause the first stage to operate at a first frequency and cause the second stage to operate at a second frequency, wherein the first frequency is greater than the second frequency.

6. The voltage regulator of claim 5, wherein the magnetic storage element is an inductor.

7. The voltage regulator of claim 5, wherein the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate in parallel.

8. The voltage regulator of claim 5, wherein the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate in anti-phase.

9. The voltage regulator of claim 5, wherein the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate independently.

10. The voltage regulator of claim 5, wherein the controller is coupled to the input voltage terminal, the output voltage terminal, and the ground terminal and is configured to receive operating information from each of the plurality of voltage regulators.

11. The voltage regulator of claim 10, wherein the operating information comprises at least one of the first operating frequency, the second operating frequency, and at least one reference voltage.

12. The voltage regulator of claim 11, wherein the controller is configured to provide an adjustment command to at least one of the switched-inductor regulator and the switched-capacitor regulator to adjust operation of the voltage regulator.

13. A voltage regulator comprising:

a multi-stage regulator configured to convert an input voltage to an output voltage, wherein the multi-stage regulator comprises at least a switched-inductor regulator and a switched-capacitor regulator; and

a controller configured to;

compare the output voltage to a reference voltage to determine a first operating frequency of the switched-inductor regulator and a second operating frequency of the switched-capacitor regulator; and

cause the switched-inductor regulator to operate at the first operating frequency, and cause the switched-capacitor regulator to operate at the second operating frequency, thereby causing the voltage regulator to provide the output voltage based on the reference voltage.

14. The voltage regulator of claim 13, wherein the controller is configured to:

cause the switched-inductor regulator to operate at the first operating frequency by providing a control signal to the switched-inductor regulator; and

cause the switched-capacitor regulator to operate at the second operating frequency by providing a control signal to the switched-capacitor regulator.

15. The voltage regulator of claim 13, wherein the first operating frequency is higher than the second operating frequency.

16. The voltage regulator of claim 13, wherein, based on the control signal, the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate in parallel.

17. The voltage regulator of claim 13, wherein, based on the control signal, the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate in anti-phase.

18. The voltage regulator of claim 13, wherein, based on the control signal, the controller is configured to:

cause the switched-inductor regulator and the switched-capacitor regulator to operate independently.

19. The voltage regulator of claim 13, wherein the controller is coupled to the input voltage terminal, the output voltage terminal, and the ground terminal and is configured to receive operating information from each of the plurality of voltage regulators and wherein the operating information comprises at least one of the first operating frequency, the second operating frequency, and at least one reference voltage.

20. The voltage regulator of claim 13, wherein the controller is configured to provide an adjustment command to at least one of the switched-inductor regulator and the switched-capacitor regulator to adjust operation of the voltage regulator.