Switched Mode Power Supply Circuit

• US 20150229149A1
• Filed: 01/23/2015
• Published: 08/13/2015
• Est. Priority Date: 02/13/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Fahlenkamp, Marc, Keitel-Schulz, Doris, Rossi, Sergio, Krueger, Martin, Wald, Christian
• Granted Patent: US 9,887,564 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/0006 Arrangements for supplying an adequate voltage to the control circuit of converters
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 1/0025 Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• 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

A switched mode power supply circuit includes a switching converter receiving an input voltage and generating an output voltage from the input voltage in accordance with a switching signal. A switching controller unit is configured to generate the switching signal in accordance with a control parameter set such that the output voltage matches a set-point.

Claims

1. A switched mode power supply circuit comprising:

a switching converter receiving an input voltage and generating an output voltage from the input voltage in accordance with a switching signal;

a switching controller unit configured to generate the switching signal in accordance with a control parameter set such that the output voltage approximately matches a set-point that is set in accordance with a selection signal; and

a detection circuit configured to detect a change of the set-point and to signal the changed set-point to the switching controller unit,

wherein the switching controller unit is further configured to update the control parameter set in response to a detected change of a set-point value.

2. The switched mode power supply circuit of claim 1, further comprising a voltage controller that receives the set-point and a signal representing the output voltage, the voltage controller being configured to generate a feedback signal based on the set-point and the signal representing the output voltage.

3. The switched mode power supply circuit of claim 2, wherein the feedback signal is supplied to the switching controller via a galvanically isolating signal path.

4. The switched mode power supply circuit of claim 1,

wherein the detection circuit is configured to receive the selection signal and to forward it to the switching controller unit via a first galvanically isolating signal path;

and

the switching controller unit being configured to update the control parameter set in accordance with the selection signal received via the galvanically isolating signal path.

5. The switched mode power supply circuit of claim 1,

wherein the switching converter includes a primary winding, a secondary winding and an auxiliary winding, the primary winding operably carrying a primary current, the secondary winding operably carrying a secondary current, and the auxiliary winding operably providing a first voltage signal;

and

wherein the switching converter includes a semiconductor switch coupled in series to the primary winding for switching the primary current on and off in accordance with the switching signal.

6. The switched mode power supply circuit of claim 5,

wherein the detection circuit is configured to receive the first voltage signal and derive therefrom the value of a current set-point and to signal the current set-point to the switching controller unit;

and

the switching controller unit being configured to update the control parameter set in accordance with the value of the current set-point signaled by the detection circuit.

7. The switched mode power supply circuit of claim 5,

wherein the detection circuit is configured to receive the selection signal and to forward it to the switching controller unit via a first galvanically isolating signal path;

and

the switching controller unit being configured to update the control parameter set in accordance with the selection signal received via the galvanically isolating signal path.

8. The switched mode power supply circuit of claim 7, wherein the switching controller includes a voltage controller that receives the set-point and a signal representing the output voltage, which is estimated from the first voltage signal.

9. The switched mode power supply circuit of claim 1, further comprising an over-voltage detection circuit that receives a signal representing the output voltage and that is configured to provide, to the switching controller unit, an over-voltage signal based on the received signal representing the output voltage.

10. The switched mode power supply circuit of claim 9,

wherein the over-voltage detection circuit senses the output voltage;

and

wherein the over-voltage signal is transmitted to the switching controller unit via a galvanically isolating signal path.

11. The switched mode power supply circuit of claim 9,

wherein the switching converter includes a primary winding, a secondary winding and an auxiliary winding, the primary winding operably carrying a primary current, the secondary winding operably carrying a secondary current, and the auxiliary winding operably providing a first voltage signal;

wherein the switching converter includes a semiconductor switch coupled in series to the primary winding for switching the primary current on and off in accordance with the switching signal; and

wherein the over-voltage detection circuit receives the first voltage and generates therefrom a signal representing the output voltage.

12. The switched mode power supply of claim 1, further comprising a communication interface configured to receive commands over a communication bus and to generate the selection signal based on the received commands.

13. The switched mode power supply of claim 12,

wherein the communication interface receives, over the communication bus, commands from an electronic device supplied with the output voltage generated by the switching converter;

and

wherein the communication interface generates a selection signal when receiving a corresponding selection command from the electronic device.

14. A power conversion method comprising:

receiving, from an input power source, an input voltage by a switching power converter;

generating, using the switching converter, an output voltage from the input voltage in accordance with a switching signal;

generating, using a switching controller, the switching signal in accordance with a control parameter set such that the output voltage approximately matches a set-point that is set in accordance with a selection signal;

detecting a change of the set-point and signaling the changed set-point to the switching controller; and

updating the control parameter set in response to a detected change of a set-point value.

15. The power conversion method of claim 14, wherein signaling the changed set-point to the switching controller comprises transmitting the selection signal via a galvanically isolating transmission path.

16. A switched mode power supply circuit comprising:

a switching converter configured to receive an input voltage and to generate an output voltage from the input voltage in accordance with a switching signal, the switching converter including a transformer to provide a galvanic isolation between a primary side and a secondary side of the switching converter; and

a switching controller unit configured to generate the switching signal in accordance with a control parameter set and dependent on input data received via a galvanically isolated transmission path, wherein the input data includes a serial data stream provided by a load supplied with the output voltage.

17. The switched mode power supply circuit of claim 16, wherein the switching controller unit is configured to generate the switching signal such that the output voltage approximately matches a set-point value which is included in the input data.

18. The switched mode power supply circuit of claim 17, wherein the switching controller unit is further configured to update the control parameter set in response to a detected change of the set-point value.

19. The switched mode power supply circuit of claim 16, wherein the galvanically isolated transmission path includes a second transformer.

20. The switched mode power supply circuit of claim 19, wherein the second transformer comprises a coreless transformer integrated in the same chip or chip package as the switching controller unit.

21. The switched mode power supply circuit of claim 16, further comprising a voltage sense circuit configured to provide a signal representing the output voltage, the signal representing the output voltage being transmitted to the switching controller unit via the galvanically isolated transmission path.

22. The switched mode power supply circuit of claim 21, wherein the switching controller unit includes a voltage controller that receives a set-point and the signal representing the output voltage and is configured to generate the switching signal based on the set-point and the signal representing the output voltage.

23. The switched mode power supply circuit of claim 16, further comprising a buffer circuit coupled to an output of the switching converter and configured to provide a signal representing output current supplied to a load connected to the output.

24. The switched mode power supply circuit of claim 23, wherein the signal representing the output current is transmitted to the switching controller unit via the galvanically isolated transmission path.

25. The switched mode power supply circuit of claim 24, wherein at least a portion of the input data is received by the switching controller unit by decoding a modulation of the output current.

26. The switched mode power supply circuit of claim 16, wherein the serial data stream is received from a load supplied with the output voltage via at least one data line coupled to the switching controller unit via the galvanically isolated transmission path.

27. The switched mode power supply circuit of claim 16, wherein the switching controller unit is configured to transmit output data to a mobile device via the galvanic isolation.

28. The switched mode power supply circuit of claim 16, wherein the switching controller unit is galvanically isolated from all electronic components galvanically coupled to the secondary side of the switching converter.

29. The switched mode power supply circuit of claim 16, wherein the switching converter includes a synchronous rectifier configured to rectify a secondary current of the switching converter.

30. The switched mode power supply circuit of claim 29, wherein the switching controller unit is configured to generate a drive signal for the synchronous rectifier, the drive signal to be transmitted to the synchronous rectifier via a galvanically isolating transmission path.

31. A charging circuit for charging a battery included in a mobile device, the charging circuit comprising:

a switching converter configured to receive an input voltage and to generate an output voltage for the mobile device from the input voltage in accordance with a switching signal, the switching converter including a transformer that provides a galvanic isolation between a primary side and a secondary side of the switching converter; and

a switching controller unit configured to generate the switching signal in accordance with a control parameter set and dependent on input data received via a galvanically isolated transmission path, wherein the input data includes a serial data stream provided by the mobile device supplied with the output voltage.

32. The charging circuit of claim 31, wherein the switching controller unit is configured to generate the switching signal such that the output voltage approximately matches a set-point that is included in the input data.

33. The charging circuit of claim 32 wherein the input data includes information concerning at least one of charging mode, battery status, desired output voltage or current.

34. The charging circuit of claim 31, wherein the switching controller is configured to transmit output data to the mobile device via the galvanically isolated transmission path.

35. The charging circuit of claim 34, wherein the output data includes information concerning at least one of a set of possible values of the output voltage, a maximum output voltage, or available charging modes.

36. The charging circuit of claim 31, wherein the switching controller unit includes a programmable processor.

37. The charging circuit of claim 31, wherein no programmable processor is connected to the secondary side of the charging circuit without an intervening galvanic isolation.

38. The charging circuit of claim 31, wherein the switching controller unit is configured to transmit output data to the mobile device via the galvanic isolation.