Raydium Semiconductor Corporation

Shu-Kuang Chou

Chih-Wei Chu

Yung-Hsiang Yang

Yu-En Lee

A LED driving apparatus and an operating method thereof are disclosed. The LED driving apparatus includes a power, at least one LED string, a LED control unit, and an input voltage detection circuit. At least one LED string is coupled to the power and includes LEDs connected in series. The input voltage detection circuit is coupled to two ends of at least one LED of the LEDs respectively and used to judge whether an input voltage is lower than a LED conducting voltage. The input voltage detection circuit includes a charging capacitance to be charged when the at least one LED string is conducted. If the judged result of the input voltage detection circuit is yes, the input voltage detection circuit will control the charging capacitance having a charging voltage to discharge to the at least one LED string.

LED driving apparatus and operating method thereof

A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a voltage generating module. The light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a preset voltage and an activation voltage and includes a light-emitting end, a control end, and a setting end. The light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other. The voltage generating module includes a plurality of control units and provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units.

Driving circuit

A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a bias current module, wherein the light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a reference voltage and a critical activation voltage and includes a light-emitting end and a bias end opposite to the light-emitting end, wherein the light-emitting end is coupled with the light-emitting units, and the bias ends of the switches are coupled with each other. The bias current module is coupled with the bias ends of the switches and has an operating bias voltage varying according to the frequency, wherein each switch is driven to be activated or to be deactivated according to a relation of the critical activation voltage and a difference between the reference voltage and the operating bias voltage.

Growing community of inventors

Taipei, Taiwan

Shu-Kuang Chou