Fairchild Korea Semiconductor Ltd.

Jae-yong Lee

Young-Je Lee

Gye-Hyun Cho

Ji-Hoon Jang

Ilyong Jung

Seung Woo Hong

Seunguk Yang

Seung-Woo Hong

Byung Kwon Choi

Jinkyum Kim

Provided are a switch control device, a switch control method, and a power supply device. The present invention generates power voltage required to operate the switch control device by using full-wave current rectification voltage generated by rectifying an AC input and detects a zero cross-point when a full-wave rectification voltage is zero voltage by using the edge of power voltage. The present invention generates a reference signal synchronized to the full-wave rectification voltage by using the detected zero cross-point and controls a switching operation of a power switch by comparing a reference signal with current which flows on the power switch.

Switch control device with zero-cross point estimation by edge detection, power supply device comprising the same, and switch control method with zero-cross point estimation by edge detection

The present invention relates to a switch controller, a switch control method, and a power supply including the switch controller. An exemplary embodiment of the present invention detects an on-time of a power switch of the power supply and decreases a frequency of a clock signal according to a period during which the detected on-time is shorter than or equal to the minimum on-time. According to the exemplary embodiment, switching of the power switch is controlled according to a clock signal, and the minimum on-time is an on period of the power switch that cannot be shortened.

Switch controller, switch control method, and power supply device comprising the switch controller

Embodiments of the present invention relate to a switch control circuit, a switch control method, and a power supply device using the same. Embodiments generate a reference signal according to a full-wave rectification voltage and control a switching operation of a power switch according to a comparing result of a sense voltage corresponding to a current flowing to the power switch and the reference voltage. Embodiments determine whether a line is opened between a first output terminal and a second output terminal of the power supply device using the sense voltage. When the line is opened, Embodiments turn off the protection switch.

Switch control circuit, switch controlling method, and power supply device using the switch control circuit

The present invention relates to a switch control circuit, a switch control method, and a converter using the same. An input voltage rectified from an AC input in a converter is transmitted to an inductor, and output power is generated from an inductor current by the input voltage. The converter includes a power switch connected to the inductor to control the inductor current and a sense resistor having a first end connected to a ground and a second end connected to the AC input. At a time point that a sense voltage generated in the sense voltage reaches the peak point and then decreased to an on-reference voltage, the power switch is turned on. The on-reference voltage is a sense voltage at a resonance start time point between a parasite capacitor of the power switch and the inductor.

Switch control circuit, converter using the same, and switch controlling method

A power supply has a TRIAC dimmer, and an AC-DC converter connected to the TRIAC dimmer. The AC-DC converter has a power switch, a bleed switch, and a controller. The controller turns off the bleed switch in a first time duration and turns on the bleed switch in a second time duration. Magnitude of a current of the power switch in the first time duration is larger than magnitude of a current of the power switch in the second time duration. Magnitude of a current of the bleed switch in a third time duration within the second time duration is smaller than magnitude of a current of the bleed switch in a fourth time duration within the second time duration.

Apparatus for controlling bleed switch, power supply, and method for driving power supply

An apparatus for driving an LED device having a plurality of LED channels is disclosed. Each LED channel has a plurality of LEDs connected in series. A power converter converts an input voltage into an output voltage and outputs the output voltage to an output terminal that is connected to first terminals of the plurality of LED channels. A plurality of current controllers are connected to second terminals of the plurality of LED channels, respectively. Each current controller controls a current of a corresponding LED channel. A detection controller determines a detection time based on voltages of the second terminals of the plurality of LED channels. A state detector detects the open-circuited states of the plurality of LED channels based on voltages of the second terminals of the plurality of LED channels at the detection time.

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Seongnam, South Korea

Jae-yong Lee