Integrated light-emitting diode driver circuit and method of operating the same

• US 9,351,379 B2
• Filed: 12/31/2014
• Issued: 05/24/2016
• Est. Priority Date: 07/04/2014
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Nian, Chia-Jung, Chou, Ching-Ho
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Kaiser, Syed M
• Application Number:
  US14/587,753
• Publication Number:
  US 20160007428A1
• Time in Patent Office: 510 Days
• Field of Search: 315/291, 315/297, 315/307, 315/224, 315/192
• US Class Current: 1/1
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 47/185 via power line carrier transmission

Abstract

An integrated light-emitting diode (LED) driver circuit includes a bi-directional power line communication (PLC) unit, a power conversion module, and a constant current (CC)/constant voltage (CV) control unit. The bi-directional PLC unit receives an AC voltage, and converts a modulation signal on the AC voltage to generate a light-dimming control signal. The power conversion module receives the AC voltage and converts the AC voltage to generate an output voltage. The CC/CV control unit receives the light-dimming control signal to generate a dimming constant current or a dimming constant voltage. The integrated LED driver circuit outputs the dimming constant current or the dimming constant voltage and the output voltage to drive a LED string.

Claims

1. An integrated light-emitting diode driver circuit, comprising:

a bi-directional power line communication unit comprising a microcontroller, the microcontroller being configured to receive an AC voltage and a conversion voltage as an operation voltage of the microcontroller, and to generate a voltage signal based on the AC voltage, the bi-directional powerline communication unit being configured to convert the voltage signal to generate a modulation signal and to generate a light-dimming control signal based on the modulation signal;

a power conversion module configured to receive the AC voltage and to convert the AC voltage to generate an output voltage; and

a constant current/constant voltage control unit configured to receive the light-dimming control signal and to generate a constant light-dimming current or a constant light-dimming voltage,

wherein the integrated light-emitting diode driver circuit is configured to output the constant light-dimming current or the constant light-dimming voltage and to output the output voltage to drive a light-emitting diode string configured to be driven by the light-emitting diode driver circuit.

2. The integrated light-emitting diode driver circuit of claim 1, further comprising:

a rectifying and filtering unit configured to receive the constant light-dimming current or the constant light-dimming voltage and the output voltage, and to rectify and filter the constant light-dimming current or the constant light-dimming voltage and the output voltage to generate a driving voltage to drive the light-emitting diode string.

3. The integrated light-emitting diode driver circuit of claim 1, wherein the bi-directional power line communication unit further comprises:

an optical coupler configured to receive the voltage signal and to convert the voltage signal to generate the modulation signal; and

a light-dimming signal generator configured to receive the modulation signal to generate the light-dimming control signal.

4. The integrated light-emitting diode driver circuit of claim 3, wherein the power conversion module comprises:

a power filtering unit configured to receive the AC voltage from the microcontroller to filter electromagnetic noises in the AC voltage and to output a filtering voltage;

a full-wave rectifying unit configured to receive the filtering voltage, to rectify the filtering voltage, and to output a rectifying voltage;

a power switching unit configured to receive the rectifying voltage and to convert the rectifying voltage to output a switching voltage; and

a main transformer configured to receive the switching voltage and to convert the switching voltage to output the output voltage.

5. The integrated light-emitting diode driver circuit of claim 3, wherein the bi-directional power line communication unit further comprises:

a voltage level converter configured to convert a supplying voltage output by the constant current/constant voltage control unit to an operation voltage of the light-dimming signal generator.

6. The integrated light-emitting diode driver circuit of claim 4, wherein the power conversion module further comprises:

an auxiliary transformer configured to receive the rectifying voltage and and to convert the rectifying voltage to output a control voltage as an operation voltage of the constant current/constant voltage control unit.

7. The integrated light-emitting diode driver circuit of claim 2, wherein the bi-directional power line communication unit, the power conversion module, the constant current/constant voltage control unit, and the rectifying and filtering unit are integrated into a module.

8. A method of operating an integrated light-emitting diode driver circuit, the method comprising:

generating a voltage signal based on a received AC voltage, the voltage signal being generated by a microcontroller of a bi-directional power line communication unit configured to receive the AC voltage and a conversion voltage, the conversion voltage being an operation voltage of the microcontroller;

generating a light-dimming control signal based on a modulation signal generated by the bi-directional power line communication unit, the modulation signal being generated based on the voltage signal;

converting the AC voltage to generate an output voltage, the output voltage being generated by a power conversion module configured to receive the AC voltage;

generating a constant light-dimming current or a constant light-dimming voltage by a constant current/constant voltage control unit configured to receive the light-dimming control signal; and

outputting the constant light-dimming current or the constant light-dimming voltage and the output voltage from the integrated light-emitting diode driver circuit to drive a light-emitting diode string configured to be driven by the light-emitting diode driver circuit.

9. The method of operating the integrated light-emitting diode driver circuit of claim 8, further comprising:

rectifying and filtering the constant light-dimming current or the constant light-dimming voltage and the output voltage by a rectifying and filtering unit to generate a driving voltage to drive the light-emitting diode string.

10. The method of operating the integrated light-emitting diode driver circuit of claim 8, wherein

an optical coupler of the bi-directional power line communication unit receives the voltage signal and converts the voltage signal to generate the modulation signal;

and

a light-dimming signal generator of the bi-directional power line communication unit receives the modulation signal to generate the light-dimming control signal.

11. The method of operating the integrated light-emitting diode driver circuit of claim 8, wherein

a power filtering unit of the power conversion module receives the AC voltage from the microcontroller to filter electromagnetic noises in the AC voltage to output a filtering voltage;

a full-wave rectifying unit of the power conversion module receives the filtering voltage and rectifies the filtering voltage to output a rectifying voltage;

a power switching unit of the power conversion module receives the rectifying voltage and converts the rectifying voltage to output a switching voltage; and

a main transformer of the power conversion module receives the switching voltage and converts the switching voltage to output the output voltage.

12. The method of operating the integrated light-emitting diode driver circuit of claim 10, wherein

a voltage level converter of the bi-directional power line communication unit converts a supplying voltage output by the constant current/constant voltage control unit to an operation voltage of the light-dimming signal generator.

13. The method of operating the integrated light-emitting diode driver circuit of claim 11, wherein

an auxiliary transformer of the power conversion module receives the rectifying voltage and converts the rectifying voltage to output a control voltage as an operation voltage of the constant current/constant voltage control unit.

14. The method of operating the integrated light-emitting diode driver circuit of claim 9, wherein the driving voltage is output to the light-emitting diode string from an integrated module comprising the bi-directional power line communication unit, the power conversion module, the constant current/constant voltage control unit, and the rectifying and filtering unit.