Novatek Microelectronics Corp.

Lan-Ting Hsu

Tsung-Hau Chang

Hsing-Chien Yang

Wen-Hsin Cheng

Ying-Hao Hsu

Chih-Yuan Hsieh

Chen-Ming Hung

Maung Maung Win

A light-emitting diode (LED) driving circuit includes an LED control circuit and a power stage circuit. The LED control circuit shifts an input pulse width modulation (PWM) signal toward a higher frequency direction in a frequency domain to generate an output PWM signal having a duty cycle substantially the same as a duty cycle of the input PWM signal. The power stage circuit outputs an LED driving current according to the output PWM signal.

LED device, LED driving circuit and method

An isolated configuration dimmer circuit of a light emitting diode (LED) applied to a conventional triac dimmer and a dimmer method are provided. When a dimmer phase angle of the triac dimmer is regulated, a second side winding of a transformer of the isolated configuration produces a pulse width corresponding to a modulated alternating current (AC) voltage, so as to regulate the pulse width of a driving signal output by the second side winding of the transformer. In addition, the dimmer circuit regulates the magnitude of a current flowing through the light emitting diode (LED) according to the pulse width corresponding to the modulated AC voltage. Accordingly, the dimmer circuit regulates the pulse width and the magnitude of the current flowing through the LED according to the dimmer phase angle of the triac dimmer. Therefore, a dimmer range of the LED can be increased.

Dimmer circuit of light emitting diode and isolated voltage generator and dimmer method thereof

Growing community of inventors

Hsinchu, Taiwan

Lan-Ting Hsu