Power converter controller with multiple power sources

Patent metadata

Field	Value
Publication number	US-9331587-B2
Application number	US-201313747089-A
Country	US
Kind code	B2
Filing date	Jan 22, 2013
Priority date	Jan 22, 2013
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A controller includes a bypass terminal, a first power circuit, a second power circuit, and a charging control circuit. The bypass terminal is to be coupled to a bypass capacitor coupled to a secondary side of an isolated power converter. The first power circuit is coupled to the bypass terminal and a first terminal to be coupled to a first node of the secondary side. The first power circuit transfers charge from the first terminal to the bypass terminal for storage on the bypass capacitor. The second power circuit is coupled to the bypass terminal and a second terminal to be coupled to a second node of the secondary side. The second power circuit transfers charge from the second terminal to the bypass terminal for storage on the bypass capacitor. The charging control circuit controls which of the first and second power circuits transfers charge to the bypass terminal.

First claim

What is claimed is:

1. A controller for use in an isolated power converter having an energy transfer element for transferring energy between a primary side and a secondary side of the power converter, the controller comprising:
a bypass terminal to be coupled to a bypass capacitor included in and coupled to the secondary side of the isolated power converter;
a first power circuit coupled between the bypass terminal and a first terminal, wherein the first terminal is to be coupled to receive charge from a secondary winding of the energy transfer element on the secondary side, and wherein the first power circuit is coupled between the bypass terminal and the first terminal to transfer the charge from the first terminal to the bypass terminal for storage on the bypass capacitor;
a second power circuit coupled between the bypass terminal and a second terminal, wherein the second terminal is to be coupled to receive charge from an output of the power converter on the secondary side, and wherein the second power circuit is coupled between the bypass terminal and the second terminal to transfer the charge from the second terminal to the bypass terminal for storage on the bypass capacitor; and
a charging control circuit coupled to control which of the first and second power circuits transfers charge to the bypass terminal in response to at least one of a bypass voltage developed at the bypass terminal and a voltage at the second terminal.

2. The controller of claim 1 , wherein the voltage at the second terminal is a regulated output voltage.

3. The controller of claim 1 , wherein the charging control circuit is coupled to control which of the first and second power circuits transfers charge to the bypass terminal in response to a comparison between the bypass voltage and the voltage at the second terminal.

4. The controller of claim 1 , wherein the charging control circuit is coupled to disable the first power circuit to disconnect the bypass terminal from the first terminal, and wherein the charging control circuit is coupled to enable the first power circuit to transfer charge from the first terminal to the bypass terminal.

5. The controller of claim 1 , wherein the charging control circuit is coupled to disable the second power circuit to disconnect the bypass terminal from the second terminal, and wherein the charging control circuit is coupled to enable the second power circuit to transfer charge from the second terminal to the bypass terminal.

6. The controller of claim 1 , further comprising a bypass regulation circuit coupled to sense the bypass voltage, determine whether the bypass voltage is less than a regulation voltage, and indicate to the charge control circuit whether the bypass voltage is less than the regulation voltage, wherein the charge control circuit is coupled to control at least one of the first and second power circuits to transfer charge to the bypass terminal when the bypass voltage is less than the regulation voltage.

7. The controller of claim 1 , wherein the charging control circuit is coupled to disable the first power circuit when the voltage at the second terminal is greater than the bypass voltage by a threshold voltage value, wherein the first power circuit blocks the transfer of charge from the first terminal to the bypass terminal when the first power circuit is disabled, and wherein the charging control circuit is coupled to enable the second power circuit to transfer charge from the second terminal to the bypass terminal when the voltage at the second terminal is greater than the bypass voltage by the threshold voltage value.

8. The controller of claim 1 , wherein the charging control circuit is coupled to disable the second power circuit when the voltage at the second terminal is less than a sum of the bypass voltage and a threshold voltage value, wherein the second power circuit blocks the transfer of charge from the second terminal to the bypass terminal when the second power circuit is disabled, and wherein the charging control circuit is coupled to enable the first power circuit to transfer charge from the first terminal to the bypass terminal when the voltage at the second terminal is less than the sum of the bypass voltage and the threshold voltage value.

9. The controller of claim 1 , wherein the charging control circuit includes a plurality of logic gates, and wherein the first power circuit is coupled to transfer charge from the first terminal to the bypass terminal when the bypass voltage is less than or equal to a minimum operating voltage of the plurality of logic gates.

10. The controller of claim 1 , further comprising a secondary switching circuit coupled to transmit a signal to a primary side of the isolated power converter, wherein the secondary switching circuit is coupled to receive operating power from the bypass terminal.

11. The controller of claim 1 , further comprising a secondary switching circuit coupled to communicate a control signal to a primary-side controller on the primary side of the power converter via a communication link, wherein the primary-side controller controls a state of a power switch included in the primary side in response to the control signal to regulate the transfer of energy from the primary side to the secondary side of the power converter.

12. An integrated circuit package for use in an isolated power converter having an energy transfer element for transferring energy between a primary side and a secondary side of the power converter, the integrated circuit package comprising:
a secondary controller comprising:
a first terminal, a second terminal, and a bypass terminal, wherein the bypass terminal is to be coupled to a bypass capacitor included in and coupled to a secondary side of an isolated power converter;
a first power circuit coupled between the bypass terminal and the first terminal to transfer charge from the first terminal to the bypass terminal for storage on the bypass capacitor, wherein the first terminal is to be coupled to receive the charge from a secondary winding of the energy transfer element on the secondary side;
a second power circuit coupled between the bypass terminal and the second terminal to transfer charge from the second terminal to the bypass terminal for storage on the bypass capacitor, wherein the second terminal is to be coupled to receive the charge from an output of the power converter on the secondary side;
a charging control circuit coupled to control which of the first and second power circuits transfers charge to the bypass terminal in response to at least one of a bypass voltage developed at the bypass terminal and a voltage at the second terminal; and
a secondary switching circuit coupled to transmit a signal to a primary side of the isolated power converter;

a primary controller coupled to receive the transmitted signal and control a power switch in response to the transmitted signal to regulate the transfer of energy from the primary side to the secondary side of the power converter; and
an encapsulation, wherein the primary controller and the secondary controller are disposed within the encapsulation.

13. The integrated circuit package of claim 12 , wherein the primary controller and the secondary controller are galvanically isolated from one another.

14. The integrated circuit package of claim 12 , further comprising the power switch, wherein the power switch is disposed within the encapsulation.

15. The integrated circuit package of claim 12 , further comprising a lead frame, wherein the secondary switching circuit is coupled to transmit the signal to the primary controller via the lead frame.

Assignees

• Power Integrations Inc

Inventors

• Djenguerian Alex B
• Liu Sheng
• Lund Leif

Classifications

• H02M3/33523 Primary

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title

• H02M3/33515 Primary

  with digital control · CPC title

• H02M3/33592

  having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer · CPC title

• Y02B70/1475

  Cross-Sectional Technologies · mapped topic

• H02M2001/0006

  Electricity · mapped topic