Power converter controller with multiple power sources

Patent metadata

Field	Value
Publication number	US-10243471-B2
Application number	US-201615087887-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Jan 22, 2013
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

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

2. The secondary controller of claim 1 , wherein the voltage at the output of the isolated power converter is a regulated output voltage.

3. The secondary controller of claim 1 , wherein the charging control circuit is coupled to control which of the first and second power circuits through which charge is transferred to the bypass capacitor in response to a comparison between the bypass voltage and the voltage at the output of the isolated power converter.

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

5. The secondary controller of claim 1 , wherein the charging control circuit is coupled to disable the second power circuit, and wherein the charging control circuit is coupled to enable the second power circuit to transfer charge from the output of the isolated power converter through the second power circuit to the bypass capacitor.

6. The secondary 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 through said at least one of the first and second power circuits to the bypass capacitor when the bypass voltage is less than the regulation voltage.

7. The secondary controller of claim 1 , wherein the charging control circuit is coupled to disable the first power circuit when the voltage at the output of the isolated power converter is greater than the bypass voltage by a threshold voltage value, wherein the first power circuit blocks the transfer of charge from the secondary winding through the first power circuit to the bypass capacitor 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 output of the isolated power converter through the second power circuit to the bypass capacitor when the voltage at the output of the isolated power converter is greater than the bypass voltage by the threshold voltage value.

8. The secondary controller of claim 1 , wherein the charging control circuit is coupled to disable the second power circuit when the voltage at the output of the isolated power converter 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 output of the isolated power converter through the second power circuit to the bypass capacitor 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 secondary winding through the first power circuit to the bypass capacitor when the voltage at the output of the isolated power converter is less than the sum of the bypass voltage and the threshold voltage value.

9. The secondary 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 secondary winding through the first power circuit to the bypass capacitor when the bypass voltage is less than or equal to a minimum operating voltage of the plurality of logic gates.

10. The secondary 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 capacitor.

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

12. A secondary controller for use in an isolated power converter, the controller comprising:
a first power circuit included in the secondary controller on a secondary side of the isolated power converter and coupled to a first node of a secondary winding of an energy transfer element on the secondary side of the isolated power converter, wherein the first power circuit is coupled to transfer charge from the first node through the first power circuit to a bypass capacitor, wherein the bypass capacitor is coupled to provide operating power to circuits of the secondary side of the isolated power converter;
a second power circuit included in the secondary controller on the secondary side of the isolated power converter and coupled to an output node of the isolated power converter for delivering a regulated output voltage, wherein the second power circuit is coupled to transfer charge from the output node through the second power circuit to the bypass capacitor to provide the operating power to the circuits of the secondary side of the isolated power converter; and
a charging control circuit coupled to control which of the first and second power circuits through which charge is transferred to the bypass capacitor to provide the operating power to the circuits of the secondary side of the isolated power converter in response to a bypass voltage developed across the bypass capacitor and a voltage at the output node, wherein the bypass capacitor is coupled between the secondary controller and a secondary ground on the secondary side of the isolated power converter.

13. The secondary controller of claim 1 , wherein the first power circuit transfers charge from the secondary winding through the first power circuit to the bypass capacitor.

14. The secondary controller of cl

Assignees

• Power Integrations Inc

Inventors

• Djenguerian Alex B
• Liu Sheng
• Lund Leif

Classifications

• H02M3/33515 Primary

  with digital control · CPC title

• H02M3/33523 Primary

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

• H02M3/33592

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

• H02M2001/0006

  Electricity · mapped topic

• Y02B70/1475

  Cross-Sectional Technologies · mapped topic