Silergy Semiconductor Technology (hangzhou) Ltd

Hangzhou Silergy Semiconductor Technology Ltd

Shenglun Chen

Wei P Chen

Xiaoru Xu

Jin Jin

The present invention relates to an SCR dimming circuit and method for regulating the luminance of an LED load. In one embodiment, an SCR dimming circuit can include: an SCR element that generates a lack-phase AC voltage based on a sinusoidal AC supply; a rectifier bridge that generates a lack-phase DC voltage based on the lack-phase AC voltage; a conduction angle generator that receives the lack-phase DC voltage, and generates a controlling signal representative of a conduction angle of the SCR element; and a dimming signal generator that generates a dimming signal to regulate luminance of the LED load, where the dimming signal generator receives the controlling signal, an adjustable signal, and a clamping voltage, an amplitude of a dimming phase angle range is selected by a fixed signal determined by the clamping voltage, and the dimming phase angle range may be shifted by regulating the adjustable signal.

SCR dimming circuit and method

The present invention relates to a controlling circuit and controlling method for an LED driver implemented as a flyback topology. The controlling circuit may be at a primary side of a transformer of the LED driver, and include a sampling circuit, an on time sensing circuit of an output diode, a regulating signal generator, and a PWM controller. The sampling circuit may generate a sampling signal indicating output current by sampling at the primary transformer side. The on time sensing circuit can detect an on time of the output diode. The regulating signal generator can generate a regulating signal by regulating the sampling signal, a voltage reference, and the on time of the output diode. The PWM controller may generate a controlling signal to control operation of a switching device of the LED driver to maintain a substantially constant output current in accordance with the regulating signal.

Controlling circuit for an LED driver and controlling method thereof

The present invention relates to a quasi-resonant controlling and driving circuit and method for a flyback converter. In one embodiment, a controlling and driving circuit for a flyback converter, can include: a differentiation circuit configured to receive a third controlling signal and a drain-source voltage of a main power switch of the flyback converter; where the drain-source voltage is configured to be differentiated by the differentiation circuit to generate a differential voltage when the third controlling signal is active within an interval that the main power switch is shut-off; a valley voltage detection circuit coupled to the differentiation circuit, and configured to receive the differential voltage; and where a valley controlling signal is configured to be generated by the valley voltage detection circuit to achieve quasi-resonant driving for the main power switch of the flyback converter when the differential voltage crosses zero with a positive slope.

Quasi-resonant controlling and driving circuit and method for a flyback converter

The present invention relates to a silicon-controlled rectifier (SCR) dimming circuit and method for regulating the luminance of a light-emitting diode (LED) load. In one embodiment, an SCR dimming circuit can include: an SCR rectifying circuit having an SCR element that receives an AC power supply, and generates a lack-phase AC voltage; a rectifier bridge that converts the lack-phase AC voltage to a lack-phase DC voltage, where the lack-phase DC voltage is filtered through a filter capacitor to generate a smooth DC voltage; a conduction phase angle signal generator that receives the lack-phase DC voltage and generates a controlling signal indicating a conduction phase angle range of the SCR element; and a dimming signal generator that compares the controlling signal and a slope reference signal to output a dimming signal to control the luminance of the LED load.

Growing community of inventors

Hangzhou, China

Shenglun Chen