VOLTAGE CONVERTER AND VOLTAGE CONVERSION METHOD

• US 20170063243A1
• Filed: 08/24/2016
• Published: 03/02/2017
• Est. Priority Date: 08/31/2015
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Gong, Xiao Wu
• Granted Patent: US 9,991,806 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop

Abstract

Disclosed is a voltage converter and a method. The voltage converter includes: an input, an output, and a transformer including a primary winding and a secondary winding; a primary side circuit comprising at least one switch and coupled between the input and the primary winding; a secondary side control circuit coupled to the output. The primary side circuit is configured to receive a feedback signal from the secondary side control circuit. The secondary side control circuit is configured to generate an error signal based on an output signal of the voltage converter, and to modulate the error signal based on supplemental information to generate the feedback signal.

Claims

1. A voltage converter, comprising:

an input voltage node;

an output voltage node;

a transformer, the transformer including a primary winding and a secondary winding;

a primary side circuit, the primary side circuit including switch circuitry to control current received from the input voltage node through the primary winding;

a secondary side control circuit to produce an output voltage at the output voltage node, the secondary side control circuit operable to modulate an error signal associated with the output voltage based on received supplemental data to produce a feedback signal encoded to include the error signal and the supplemental data, the secondary side control circuit communicating the feedback signal to the primary side circuit.

2. The voltage converter of claim 1 further comprising:

a rectifier circuit coupled between the secondary winding and the output voltage node.

3. The voltage converter of claim 1, wherein the secondary side control circuit is operable to generate the error signal based on a signal proportional to an output signal and a reference signal of the secondary side control circuit, the secondary side control circuit further operable to adjust a proportionality factor between the output signal and the signal proportional to the output signal dependent on the supplemental data.

4. The voltage converter of claim 3, wherein the secondary side control circuit comprises a voltage divider to output the signal proportional to the output signal, and

wherein the secondary side control circuit is operable to adjust the proportionality factor via adjusting a voltage divider ratio of the voltage divider.

5. The voltage converter of claim 1, wherein the secondary side circuit is further operable to generate the supplemental data based on an output signal outputted from the output voltage node.

6. The voltage converter of claim 5, wherein the secondary side control circuit is operable to generate the supplemental data in response to detecting that a magnitude of the output signal is outside a predefined signal range.

7. The voltage converter of claim 1, wherein the primary side circuit further comprises:

a primary side control circuit operable to;

receive the feedback signal, obtain the error signal and the supplemental data from the received feedback signal, and control the switch circuitry based on the obtained error signal.

8. The voltage converter of claim 7, wherein the primary side control circuit is operable to:

i) limit a magnitude of the current through the primary winding to less than a predefined current level, and ii) set the predefined current level based on the obtained supplemental data obtained from the feedback signal.

9. The voltage converter of claim 7, wherein the primary side control circuit is operable to conditionally shut down the voltage converter depending on a state of the supplemental data obtained from the feedback signal.

10. The voltage converter of claim 1, wherein the secondary side control circuit modulates the error signal in a communication time period, the modulation including adjusting a magnitude of the error signal in accordance with a predefined pattern to convey the supplemental data in the feedback signal.

11. The voltage converter of claim 1, wherein the secondary side circuit is operable to produce the error signal based on an output voltage outputted from the output voltage node.

12. A method comprising:

via a secondary side circuit in a voltage converter;

receiving an error signal generated based on an output signal of the voltage converter;

receiving supplemental data to convey to a primary side circuit of the voltage converter;

modulating the error signal based on the supplemental data;

transmitting the modulated error signal encoded with the supplemental data as a feedback signal to the primary side circuit, the primary side circuit operable to use the feedback signal to control current through a primary winding of a transformer in the voltage converter.

13. The method of claim 12, further comprising:

generating the output signal via a rectifier circuit coupled between a secondary winding of the transformer and an output node of the voltage converter.

14. The method of claim 12, wherein generating the error signal comprises generating the error signal based on a signal proportional to the output signal and a corrg reference signal, and adjusting a proportionality factor between the output signal and the signal proportional to the output signal dependent on the supplemental data.

15. The method of claim 14, further comprising:

outputting the signal proportional to the output signal using a voltage divider; and

wherein adjusting the proportionality factor comprises adjusting a voltage divider ratio of the voltage divider.

16. The method of claim 12, further comprising:

generating the supplemental data based on a state of the output signal.

17. The method of claim 16 further comprising:

producing the supplemental data to indicate that a magnitude of the output signal is outside a predefined signal range.

18. The method of claim 12 further comprising:

via the primary side circuit;

receiving the feedback signal;

obtaining the error signal and the supplemental data from the received feedback signal; and

controlling switch circuitry in the primary side circuit using the received error signal.

19. The method of claim 18, further comprising:

via the primary side circuit;

setting a predefined current level based on the supplemental data obtained from the feedback signal; and

limiting a magnitude of the current through the primary winding to less than the predefined current level.

20. The method of claim 18, further comprising:

conditionally shutting down the voltage converter depending on a state of the supplemental data.

21. The method of claim 12 further comprising:

modulating the error signal in a communication time period, the modulation including adjusting a magnitude of the error signal in accordance with a predefined pattern to encode the feedback signal to include the supplemental data.