Light emitting diode driving circuit and lighting apparatus having the same

• US 9,510,414 B2
• Filed: 06/16/2015
• Issued: 11/29/2016
• Est. Priority Date: 10/01/2014
• Status: Active Grant

• Current Assignee: Magnachip Semiconductor Limited (Magnachip Semiconductor)
• Original Assignee: Magnachip Semiconductor Limited (Magnachip Semiconductor)
• Inventors: Kim, Hae Wook, Rowe, Brent, Greenland, Paul, Kim, Hyun Jung, Lee, Seung Hwan
• Primary Examiner(s): A, Minh D
• Application Number:
  US14/740,524
• Publication Number:
  US 20160100466A1
• Time in Patent Office: 532 Days
• Field of Search: 315307-308, 315/200.R, 315/209.R, 315/312, 315/185.R
• US Class Current: 1/1
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/31 Phase-control circuits
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations

Abstract

A light emitting diode (LED) driving circuit includes a flicker elimination unit configured to perform a flicker removal for LED modules and a driving control unit configured to pause a procedure of the flicker removal based on an AC input voltage that is regulated through a Triode for Alternating Current (TRIAC) dimmer, so as to cause a brightness of the LED modules to be dimmed. Therefore, the LED driving circuit selectively adjusts an LED brightness level and removes LED flicker by using a TRIAC dimmer and controls the brightness level of the LED module based on a dimming level.

Claims

1. A light emitting diode (LED) driving circuit comprising:

a flicker elimination unit configured to perform a flicker removal for LED modules; and

a driving control unit configured to pause the flicker removal in response to receiving an AC input voltage through a Triode for Alternating Current (TRIAC) dimmer.

2. The circuit of claim 1, wherein the flicker elimination unit comprises a diode element, a transistor element and a capacitive element.

3. The circuit of claim 2, wherein the flicker elimination unit is configured to improve a power factor by using the capacitive element to reduce a power loss.

4. The circuit of claim 1, wherein the driving control unit comprises:

a signal detection module configured to detect a selection signal received from an internal source or external source; and

a control signal supply module configured to provide a control signal for activating the flicker elimination unit based on the detection result of the selection signal.

5. The circuit of claim 4, wherein the signal detection module counts a number of oscillations output by an oscillator during one cycle of an AC input voltage to determine whether the selection signal is a TRIAC dimming signal.

6. The circuit of claim 4, wherein the control signal supply module provides the control signal to activate the flicker elimination unit in response to the selection signal not being a TRIAC dimming signal and does not provide the control signal in response to the selection signal being a TRIAC dimming signal.

7. The circuit of claim 4, wherein the driving control unit selects a TRIAC-dimming mode using the TRIAC dimmer or a flicker-free mode using the flicker elimination unit through the control signal.

8. The circuit of claim 4, wherein the driving control unit controls a path of a driving current flowing into the LED modules.

9. The circuit of claim 1, further comprising:

a dimming level control unit configured to control a brightness level of the plurality of LED modules by controlling a dimming level.

10. The circuit of claim 9, wherein the dimming level control unit receives a dimming signal from an outside source or an inside source in order to control the brightness level of the plurality of LED modules using an analog-dimming level or Pulse Width Modulation (PWM) dimming level of the dimming signal.

11. The circuit of claim 9, wherein the dimming level control unit sets an amplitude of a driving current as a predetermined amplitude level in response to the dimming signal being provided from an internal source.

12. The circuit of claim 9, wherein the dimming level control unit controls an amplitude level of a driving current in response to the dimming signal being an external analog dimming signal and controls an amplitude level or frequency level of the driving current provided that the dimming signal is an external Pulse Width Modulation (PWM) dimming signal.

13. The circuit of claim 9, further comprising:

a driving current control unit configured to control a driving current set based on whether the control signal is provided and based on the dimming level.

14. A light emitting diode (LED) lighting apparatus, comprising:

LED modules;

a bridge diode configured to full-wave rectify an AC input voltage;

a Triode for Alternating Current (TRIAC) dimmer configured to adjust a brightness level of the LED modules; and

a LED driving circuit configured to drive the LED modules

wherein the LED driving circuit comprises

a flicker elimination unit configured to perform a flicker removal for the LED modules; and

a driving control unit configured to pause the flicker removal in response to receiving an AC input voltage through the Triode for Alternating Current (TRIAC) dimmer.

15. The light emitting diode (LED) lighting apparatus of claim 14, wherein the LED driving circuit further comprises a dimming level control unit configured to control a brightness level of the LED modules by controlling a dimming level.

16. The light emitting diode (LED) light apparatus of claim 14, wherein the light emitting diode (LED) driving circuit further comprises a driving current control unit configured to control a driving current set based on whether a control signal is provided and a dimming level.

17. A driving method of an light emitting diode (LED) driving circuit comprising:

detecting a selection signal;

determining whether the selection signal is a Triode for Alternating Current (TRIAC) dimming signal; and

in response to determining that the selection signal is not a TRIAC dimming signal, providing a control signal to perform flicker removal.

18. The driving method of claim 17, further comprising:

detecting whether a dimming signal is provided from an outside source; and

in response to detecting that a dimming signal is provided from an outside source, controlling an amplitude or frequency level of a driving current.

19. The driving method of claim 18, further comprising:

determining whether a dimming signal is provided from an inside source; and

in response to determining that a dimming signal is provided from an inside source, setting an amplitude of the driving current to be a predetermined amplitude level.

20. The driving method of claim 19, further comprising:

controlling a path of the driving current.