Method and apparatus for programming a power converter controller with an external programming terminal having multiple functions

Patent metadata

Field	Value
Publication number	US-9287786-B2
Application number	US-201314133318-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Jun 15, 2011
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A power converter includes an energy transfer element and a power switch coupled the energy transfer element and an input of the power converter. A control circuit is coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of an output of the power converter. A programming interface circuit is coupled to the control circuit and a coupling switcher coupled to the programming interface circuit. A programming terminal is selectively coupled to the programming interface circuit through the coupling switcher. A programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, and is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter.

First claim

What is claimed is:

1. A power converter, comprising:
an energy transfer element coupled between an input of the power converter and an output of the power converter;
a power switch coupled the energy transfer element and the input of the power converter;
a control circuit coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of the output of the power converter to control a transfer of energy from the input of the power converter to the output of the power converter;
a programming interface circuit coupled to the control circuit;
a coupling switcher coupled to the programming interface circuit; and
a programming terminal selectively coupled to the programming interface circuit through the coupling switcher, wherein a programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, wherein the programming circuit coupled to the programming terminal is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter.

2. The power converter of claim 1 wherein substantially no power is consumed through the programming terminal when the programming circuit coupled to the programming terminal is decoupled from the programming interface circuit by the coupling switcher.

3. The power converter of claim 1 wherein the programming interface circuit includes a decoder coupled to the control circuit to select a programmable characteristic of the controller in response to a programming current through the programming terminal during the startup programming condition of the power converter.

4. The power converter of claim 3 wherein the decoder comprises a variable current source coupled to generate a decoder current representative of the programming current through the programming terminal during the startup programming condition of the power converter, wherein the control circuit selects the programmable characteristic of the controller in response to the decoder current.

5. The power converter of claim 4 wherein the decoder current is responsive to a programming impedance included in the programming circuit coupled to the programming terminal.

6. The power converter of claim 4 wherein the variable current source comprises a plurality of switched current sources to generate the decoder current representative of the programming current through the programming terminal during the startup programming condition of the power converter.

7. The power converter of claim 3 wherein the programmable characteristic of the controller includes a current limit characteristic of the controller.

8. The power converter of claim 3 wherein the programmable characteristic of the controller includes switching frequency characteristic of the power converter.

9. The power converter of claim 3 wherein the coupling switcher comprises a startup switch coupled to be activated to provide the programming current during the startup programming condition of the power converter.

10. The power converter of claim 3 wherein the coupling switcher comprises a programming comparator coupled to a programming threshold to regulate the programming current through the programming terminal in response to the programming threshold during the startup programming condition of the power converter.

11. The power converter of claim 1 wherein the programming interface circuit includes a timing circuit coupled to the programming terminal through the coupling switcher during the fault condition of the power converter.

12. The power converter of claim 11 wherein the timing circuit is coupled to provide a programmable delay time of an extended shutdown delay during an open loop fault detection condition of the power converter.

13. The power converter of claim 11 wherein the controller is coupled to cause repeated cycles of an auto restart mode in response to a detection of the fault condition, wherein switching of the power switch stops for a shutdown off-interval in response to the controller receiving of a shutdown signal and restarts and continues for a restart on-interval during the fault condition.

14. The power converter of claim 11 wherein the timing circuit is coupled to provide a programmable delay time of a switch on-interval extension in each cycle of an auto restart mode of the power converter.

15. The power converter of claim 11 wherein the coupling switcher comprises a fault switch coupled to be activated to couple the timing circuit to the programming terminal during the fault condition of the power converter.

16. The power converter of claim 11 wherein the timing circuit is coupled to provide a programmable delay in response to an RC time constant of the programming circuit coupled to the programming terminal.

17. The power converter of claim 16 wherein the timing circuit comprises a set-reset latch coupled to activate and deactivate an application of a charging current to the programming circuit through the programming terminal to provide the programmable delay during the fault condition of the power converter.

18. The power converter of claim 17 wherein the timing circuit further comprises a first comparator coupled to a lower threshold and the programming terminal, wherein the first comparator is coupled to cause the set-reset latch to activate the application of the charging current to the programming circuit through the programming terminal in response a voltage at the programming terminal being substantially equal to the lower threshold.

19. The power converter of claim 18 wherein the timing circuit further comprises a second comparator coupled to an upper threshold and the programming terminal, wherein the second comparator is coupled to cause the set-reset latch to deactivate the application of the charging current to the programming circuit through the programming terminal in response to a voltage at the programming terminal being substantially equal to the upper threshold.

20. The power converter of claim 17 wherein the timing circuit is coupled to provide the programmable delay in response to a predetermined number of cycles of activations and deactivations of the application of the charging current to the programming circuit through the programming terminal.

21. The power converter of claim 20 wherein the timing circuit further comprises a counter coupled to count the predetermined number of cycles of activations and deactivations to provide the programmable delay.

22. The power converter of claim 1 further comprising a remote off comparator coupled to a remote off threshold and the programming terminal, wherein the remote off comparator is coupled to activate a remote off function of the controller in response to a voltage at the programming terminal being substantially equal to the remote off threshold.

23. The power converter of claim 1 further comprising a latch reset comparator coupled to latch reset threshold and the programming terminal, wherein the latch reset comparator is coupled to activate a latch reset operation of the controller in response to a voltage at the programming terminal being substantially equal to the latch reset threshold.

24. The power converter of claim 1 wherein the programming interface circuit is an internal programming interface circui

Assignees

• Power Integrations Inc

Inventors

• BÄURLE Stefan
• Zhang Guangchao Darson
• Mao Mingming

Classifications

• H02M2001/0025

  Electricity · mapped topic

• H02M3/33515 Primary

  with digital control · CPC title

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M1/0025

  Arrangements for modifying reference values, feedback values or error values in the control loop of a converter · CPC title