LED driving circuit

Patent metadata

Field	Value
Publication number	US-11284487-B2
Application number	US-202016852501-A
Country	US
Kind code	B2
Filing date	Apr 19, 2020
Priority date	Nov 1, 2018
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

A LED driving circuit includes a DALI module, a linear voltage luminance adjusting module, a DIP luminance adjusting module, a control module, a power source, a constant current driving module and an output module. The DALI module generates a PWM signal. The linear voltage luminance adjusting module generates a second PWM signal. The DIP luminance adjusting module generates a switch signal. The control module generates a drive PWM signal using the first PWM signal, the second PWM signal and the switch signal. The power source provides power. The constant current driving module generates a constant-current drive voltage using the provided power and the drive PWM signal. The output module generates a drive current that responds to the constant-current drive voltage. And the output module drives an external LED device using the drive current.

First claim

What is claimed is:

1. An LED driving circuit, comprising:
a digital addressable lighting interface (DALI) module, configured to generate a first pulse-width modulation (PWM) signal;
a linear voltage luminance adjusting module, configured to generate a second pulse-width modulation signal;
a dual-in-line package (DIP) luminance adjusting module, configured to generate a switch signal;
a control module, electrically coupled to the DALI module, the linear voltage luminance adjusting module and the DIP module, and configured to generate a drive PWM signal using the first PWM signal, the second PWM signal and the switch signal;
a power source, configured to provide power;
a constant current driving module, electrically coupled to the power source and the control module, and configured to generate a constant-current drive voltage using the provided power and the drive PWM signal; and
an output module, electrically coupled to the constant current driving module, configured to generate a drive current that responds to the constant-current drive voltage, and configured to drive an external LED device using the drive current, wherein the output module comprises:
a secondary winding of a transformer, whose primary winding is disposed within the constant current driving module; and
a common-mode inductor, having a first side electrically coupled to the secondary winding, and having a second side for outputting the drive current.

2. The LED driving circuit of claim 1 , wherein the control module is further configured to generate the drive PWM signal based on a dynamic combination of PWM ratios for the first PWM signal, the second PWM signal and the switch signal.

3. The LED driving circuit of claim 1 , wherein the control module comprises:
a first PWM input terminal, electrically coupled to the linear voltage luminance adjusting module for receiving the second PWM signal;
a second PWM input terminal, electrically coupled to the DALI module for receiving the first PWM signal;
at least one switch input terminal, electrically coupled to the DIP luminance adjusting module for receiving the switch signal; and
a PWM output terminal, electrically coupled to the control module for outputting the drive PWM signal.

4. The LED driving circuit of claim 1 , wherein the DALI module comprises a DALI luminance self-adjusting chip.

5. The LED driving circuit of claim 1 , wherein the linear voltage luminance adjusting module comprises:
a linear luminance adjusting chip, having an input terminal electrically coupled to the output module for receiving the constant-current drive voltage, having at least one luminance adjusting terminal for receiving a first luminance adjusting signal, and having an output terminal for outputting a second luminance adjusting signal, wherein the linear luminance adjusting chip is configured to generate the second luminance adjusting signal based on the first luminance adjusting signal and the constant-current drive voltage; and
a photo coupler, having an input terminal electrically coupled to the output terminal of the linear luminance chip for receiving the second luminance adjusting signal, and having an output terminal for outputting a third luminance adjusting signal, wherein the photo coupler is configured to perform photo-electric conversion on the second luminance adjusting signal to generate the third luminance adjusting signal.

6. The LED driving circuit of claim 5 , wherein the linear voltage luminance adjusting module further comprises a voltage stabilizing diode, having a positive terminal electrically coupled to a ground terminal of the photo coupler and ground, and having a negative terminal electrically coupled to the output terminal of the photo coupler.

7. The LED driving circuit of claim 5 , wherein the first luminance adjusting signal is ranged between 0 volts and 10 volts in voltage level.

8. The LED driving circuit of claim 1 , wherein the DIP luminance adjusting module comprises at least one switch, each of which is electrically coupled to a switch input terminal of the control module for relaying the switch signal.

9. The LED driving circuit of claim 8 , wherein the at least one switch is further electrically coupled to a DC voltage source.

10. The LED driving circuit of claim 1 , wherein the constant current driving module comprises:
a constant current driving chip, having a PWM input terminal electrically coupled to the control module for receiving the drive PWM signal;
an N-type metal-oxide semiconductor field-effect transistor (MOSFET), having a gate electrically coupled to a drive terminal of the constant driving current chip; and
a primary winding of a transformer, having a first terminal electrically coupled to a drain of the N-type MOSFET, and having a second terminal electrically coupled to the power source.

11. The LED driving circuit of claim 10 , wherein the constant current driving module further comprises:
an npn-type bipolar junction transistor (BJT), having a base electrically coupled to an input power terminal of the constant driving chip and a DC voltage source, and having an emitter electrically coupled to the power source.

12. The LED driving circuit of claim 11 , wherein the constant current driving module further comprises:
a first diode, having a positive terminal electrically coupled to the input power terminal of the constant current driving chip, and having a negative terminal electrically coupled to the base of the npn-type BJT.

13. The LED driving circuit of claim 11 , wherein the constant current driving module further comprises:
a second diode, having a positive terminal electrically coupled to the emitter of the npn-type BJT, and having a negative terminal electrically coupled to the power source; and
a third diode, having a positive terminal electrically coupled to a first winding, and having a negative terminal electrically coupled to a collector of the npn-type BJT.

14. The LED driving circuit of claim 11 , wherein the constant current driving module further comprises:
a fourth diode, having a positive terminal electrically coupled to the gate of the N-type MOSFET, and having a negative terminal electrically coupled to the drive terminal of the N-type MOSFET.

15. The LED driving circuit of claim 11 , wherein the constant current driving module further comprises:
a first resistor, having a first terminal electrically coupled to the power source, and having a second terminal electrically coupled to the emitter of the npn-type BJT; and
a second resistor, having a first terminal electrically coupled to a source of the N-type MOSFET, and having a second terminal electrically coupled to ground.

16. The LED driving circuit of claim 11 , wherein the constant current driving module further comprises:
a capacitor, having a first terminal electrically coupled to the input power terminal of the constant current driving chip, and having a second terminal electrically coupled to the gate of the N-type MOSFET.

17. The LED driving circuit of claim 1 , wherein the output module further comprises:
a diode, having a first terminal electrically coupled to the secondary winding, and having a second terminal electrically coupled to the first side of the common-mode inductor.

18. The LED driving circuit of claim 1 , wherein the output module further comprises:
a capacitor, electrically coupled to the first side of the common-mode inductor in parallel; and
a resistor, electrically coupled to the capacitor in parallel.

19. The LED driving circuit of claim 1 , furth

Assignees

• Xiamen Eco Lighting Co Ltd

Inventors

• Wen Shuisheng
• Lin Liping
• Chen Xiaodeng

Classifications

• H05B47/183 Primary

  using digital addressable lighting interface [DALI] communication protocols · CPC title

• H05B44/00

  Circuit arrangements for operating electroluminescent light sources (for operating light emitting diodes H05B45/00) · CPC title

• H05B45/325 Primary

  Pulse-width modulation [PWM] · CPC title

• H05B45/395

  Linear regulators · CPC title

• H05B45/48

  having LEDs organised in strings and incorporating parallel shunting devices · CPC title