METHOD AND SYSTEM FOR DRIVING LED

• US 20110266967A1
• Filed: 04/29/2011
• Published: 11/03/2011
• Est. Priority Date: 04/30/2010
• Status: Abandoned Application

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Tan, Wei, Bordin, Luca, Chen, Yuli, Nie, Shijun
• Application Number:
  US13/097,115
• Publication Number:
  US 20110266967A1
• Time in Patent Office: Days
• US Class Current: 315/287
• CPC Class Codes: H05B 45/31 Phase-control circuits
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The present invention discloses an LED driving method and an LED driving system, the method comprising: generating a PWM control signal with a PWM dimming signal; and controlling a PWM DC/DC converter with the PWM control signal, so as to generate a driving voltage of the LED.

Claims

1. An LED driving method, comprising:

generating a PWM control signal with a PWM dimming signal; and

controlling a PWM DC/DC converter with the PWM control signal, so as to generate a driving voltage of the LED.

2. The method according to claim 1, wherein the frequency of the PWM dimming signal is in a range from 100 Hz to 1000 Hz.

3. The method according to claim 1 or 2, wherein the frequency of the PWM control signal is in an order of ten kilohertz to hundred kilohertz.

4. An LED driving system, comprising:

a PWM DC/DC converter (1310), a PWM controller (1320) and a PWM dimming signal generating unit (1330);

wherein;

the PWM dimming signal generating unit (1330) is configured to generate a PWM dimming signal;

the PWM controller (1320) is configured to generate a PWM control signal by utilizing the PWM dimming signal; and

the PWM DC/DC converter (1310) is configured to generate a driving voltage of LED according to the PWM control signal.

5. The system according to claim 4, wherein the frequency of the PWM dimming signal is in a range from 100 Hz to 1000 Hz.

6. The system according to claim 4 or 5, wherein the frequency of the PWM control signal is in an order often kilohertz to hundred kilohertz.

7. The system according to claim 4 or 5, further comprises a constant current control unit (1340), which is configured to control the PWM controller (1320) according to a current flowing through the LED to adjust the PWM control signal, so as to ensure that a magnitude of the current flowing through the LED maintains constant.

8. The system according to claim 7, further comprises an isolation and feedback unit (1350), which is configured to input a feedback signal from the constant current control unit (1340) to the PWM controller in an electrical isolation manner.