Resonant rectified discontinuous switching regulator with inductor preflux

• US 10,389,246 B1
• Filed: 08/29/2017
• Issued: 08/20/2019
• Est. Priority Date: 03/02/2015
• Status: Active Grant

• Current Assignee: Empower Semiconductor
• Original Assignee: Empower Semiconductor
• Inventors: Lidsky, David, Phillips, Timothy Alan, Oak, Parag
• Primary Examiner(s): Rosario-Benitez, Gustavo A
• Application Number:
  US15/689,698
• Time in Patent Office: 721 Days
• CPC Class Codes: G05F 1/10 Regulating voltage or current G05F1/02 takes precedence; for electric railways B60M3/02
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/0095 Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck
• 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 3/156 with automatic control of output voltage or current, e.g. switching regulators
• 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 switched-mode power regulator circuit has four solid-state switches connected in series and a capacitor and an inductor that regulate power delivered to a load. The solid-state switches are operated such that a voltage at the load is regulated by repetitively (1) prefluxing the inductor then charging the capacitor causing an increased current to flow in the inductor and (2) prefluxing the inductor then discharging the capacitor causing increased current to flow in the inductor. The inductor prefluxing steps enable the circuit to provide increased output voltage and/or increased output current.

Claims

1. A power conversion circuit comprising:

a plurality of serially connected solid-state switches coupled between an input terminal and a ground and including an output terminal;

an inductor coupled between the output terminal and a load;

a capacitor coupled in parallel with two of the serially connected solid-state switches; and

a controller configured to control the plurality of solid-state switches such that a voltage at the load is regulated by repetitively (1) generating a first preflux condition in the inductor and subsequently charging the capacitor causing an increase in current flow in the inductor and (2) generating a second preflux condition in the inductor and subsequently discharging the capacitor causing an increase in current flow in the inductor.

2. The power conversion circuit of claim 1 wherein the output terminal is positioned between the two serially connected solid-state switches that are coupled in parallel with the capacitor.

3. The power conversion circuit of claim 1 wherein the plurality of serially connected solid-state switches includes:

a first solid-state switch having a pair of first switch terminals and a first control terminal, the pair of first switch terminals connected between the input terminal and a first junction;

a second solid-state switch having a pair of second switch terminals and a second control terminal, the pair of second switch terminals connected between the first junction and the output terminal;

a third solid-state switch having a pair of third switch terminals and a third control terminal, the pair of third switch terminals connected between the output terminal and a third junction; and

a fourth solid-state switch having a pair of fourth switch terminals and a fourth control terminal, the pair of fourth switch terminals connected between the third junction and the ground.

4. The power conversion circuit of claim 3 wherein during the first preflux condition the first and the second solid-state switches are in an on state.

5. The power conversion circuit of claim 1 wherein a duration of the first preflux condition is controlled by one or more comparators.

6. The power conversion circuit of claim 5 wherein one of the one or more comparators has a set point that is adjusted with a variable feedback signal.

7. The power conversion circuit of claim 6 wherein the variable feedback signal is generated by a tuning algorithm configured to cause the inductor to be energized with an appropriate amount of current so current within the inductor resonates to zero at a same time as when the capacitor becomes fully charged.

8. The power conversion circuit of claim 6 wherein the variable feedback signal is generated by a tuning algorithm configured to cause the inductor to be energized with an appropriate amount of current so current within the inductor resonates to zero at a same time as when the capacitor becomes fully discharged.

9. The power conversion circuit of claim 1 disposed on a unitary semiconductor die that includes the load.

10. The power conversion circuit of claim 1 wherein the controller commands at least one of the plurality of solid-state switches to temporarily couple a power supply to the capacitor causing the capacitor to be precharged before coupling the input terminal to the load.

11. A method of operating a power conversion circuit, the method comprising:

supplying power to the power conversion circuit with a power supply connected to a first terminal, the power conversion circuit comprising;

a plurality of serially connected solid-state switches coupled between the first terminal and a ground;

a capacitor coupled in parallel with two of the serially connected solid-state switches;

a switch-node positioned between two of the serially connected solid-state switches; and

an inductor coupled between the switch-node and a load; and

turning on and off the plurality of solid-state switches such that a voltage at the load is regulated by repetitively (1) generating a first preflux condition in the inductor and subsequently charging the capacitor causing an increase in current flow in the inductor and (2) generating a second preflux condition in the inductor and subsequently discharging the capacitor causing an increase in current flow in the inductor.

12. The method of claim 11 wherein the switch-node is positioned between the two serially connected solid-state switches that are coupled in parallel with the capacitor.

13. The method of claim 11 wherein a duration of the first preflux condition is controlled by one or more comparators.

14. The method of claim 13 wherein one of the one or more comparators has a set point that is adjusted with a variable feedback signal.

15. The method of claim 14 wherein the variable feedback signal is generated by a tuning algorithm configured to cause the inductor to be energized with an appropriate amount of current so current within the inductor resonates to zero at a same time as when the capacitor becomes fully charged.

16. The method of claim 11 wherein the plurality of serially connected solid-state switches includes:

a first solid-state switch having a pair of first switch terminals and a first control terminal, the pair of first switch terminals connected between the first terminal and a first junction;

a second solid-state switch having a pair of second switch terminals and a second control terminal, the pair of second switch terminals connected between the first junction and the switch-node;

a third solid-state switch having a pair of third switch terminals and a third control terminal, the pair of third switch terminals connected between the switch-node and a third junction; and

a fourth solid-state switch having a pair of fourth switch terminals and a fourth control terminal, the pair of fourth switch terminals connected between the third junction and a ground.

17. The method of claim 16 wherein during the first preflux condition the first and the second solid-state switches are in an on state.

18. The method of claim 11 wherein at least one of the plurality of solid-state switches temporarily couples a power supply to the capacitor causing the capacitor to be precharged before coupling the first terminal to the load.

19. The method of claim 18 wherein the power supply is disposed on a unitary semiconductor die that also contains the power conversion circuit.

20. The method of claim 11 wherein the power conversion circuit and the load are disposed on a unitary semiconductor die.