LED lighting systems and methods for constant current control in various operation modes

• US 10,609,778 B2
• Filed: 08/22/2017
• Issued: 03/31/2020
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: On-Bright Electronics (Shanghai) Co., Ltd. (Orthosie Investment Holdings Ltd.)
• Original Assignee: On-Bright Electronics (Shanghai) Co., Ltd. (Orthosie Investment Holdings Ltd.)
• Inventors: Fang, Lieyi, Zhou, Jun
• Primary Examiner(s): A, Minh D
• Assistant Examiner(s): Cho, James H
• Application Number:
  US15/683,489
• Publication Number:
  US 20180042079A1
• Time in Patent Office: 952 Days
• Field of Search: None
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

System and method for providing at least an output current to one or more light emitting diodes. The system includes a control component configured to receive at least a demagnetization signal, a sensed signal and a reference signal and to generate a control signal based on at least information associated with the demagnetization signal, the sensed signal and the reference signal, and a logic and driving component configured to receive at least the control signal and output a drive signal to a switch based on at least information associated with the control signal. The switch is connected to a first diode terminal of a diode and a first inductor terminal of an inductor. The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal.

Claims

1. A system for providing at least an output current to one or more light emitting diodes, the system comprising:

a control component configured to receive at least a demagnetization signal, a sensed signal and a reference signal and to generate a control signal based on at least information associated with the demagnetization signal, the sensed signal and the reference signal; and

a logic and driving component configured to receive at least the control signal and output a drive signal to a switch based on at least information associated with the control signal;

wherein;

the switch is connected to a first diode terminal of a diode and a first inductor terminal of an inductor, the diode further including a second diode terminal, the inductor further including a second inductor terminal;

the second diode terminal and the second inductor terminal are configured to provide at least the output current to the one or more light emitting diodes; and

the control signal is configured to keep an average output current at a constant magnitude so that the average output current does not change over time.

2. The system of claim 1 wherein the sensed signal is associated with a current flowing through the switch if the switch is closed in response to the drive signal.

3. The system of claim 1 wherein the reference signal is a reference current associated with a predetermined magnitude.

4. The system of claim 1 wherein the logic and driving component includes:

a logic component configured to receive the control signal;

a flip-flop component coupled to at least the logic component; and

a drive component coupled to at least the flip-flop component and configured to generate the drive signal.

5. The system of claim 1 wherein the first inductor terminal is configured to provide at least a feedback signal, the feedback signal being associated with the demagnetization signal.

6. The system of claim 1 is configured to keep the average output current at a constant magnitude under each operation mode of a plurality of operation modes.

7. The system of claim 6 wherein the plurality of operation modes includes a discontinuous conduction mode, a continuous conduction mode and a critical conduction mode.

8. A method for providing at least an output current to one or more light emitting diodes, the method comprising:

receiving at least a demagnetization signal, a sensed signal and a reference signal;

processing information associated with the demagnetization signal, the sensed signal and the reference signal;

generating a control signal based on at least information associated with the demagnetization signal, the sensed signal and the reference signal;

receiving at least the control signal;

processing information associated with the control signal;

outputting a drive signal to a switch connected to a first diode terminal of a diode and a first inductor terminal of an inductor, the diode further including a second diode terminal, the inductor further including a second inductor terminal, the second diode terminal and the second inductor terminal being configured to provide at least the output current to the one or more light emitting diodes; and

keeping an average output current at a constant magnitude based on at least information associated with the control signal so that the average output current does not change over time.

9. The method of claim 8 wherein the first inductor terminal is configured to provide at least a feedback signal, the feedback signal being associated with the demagnetization signal.

10. The method of claim 8 wherein the keeping an average output current at a constant magnitude based on at least information associated with the control signal includes keeping the average output current at a constant magnitude under each operation mode of a plurality of operation modes.

11. The method of 10 wherein the plurality of operation modes includes a discontinuous conduction mode, a continuous conduction mode and a critical conduction mode.