Fairchild Korea Semiconductor Ltd.

Semiconductor Components Industries, LLC

Byunghak Ahn

Jin-Tae Kim

Hak-Hee Lee

Eung-Woo Lee

Moonho Choi

Jinhwa Chung

Taesung Kim

Gwanbon Koo

Seunguk Yang

Youngbae Park

Dong Jin Park

Shanmei Li

Il-Young Jung

Jaewoon Kim

Keun-Eui Hong

Frank Chang

Eunsung Jang

Jin Chenghao

Jaehan Yoon

One cable compensation circuit is connected to a shunt regulator to generate a feedback voltage corresponding to an output voltage of a power supply device. The cable compensation circuit controls cathode impedance of the shunt regulator according to the output current of the power supply device to compensate a voltage drop generated in a cable.

Cable compensation circuit

Disclosed are an LED emitting device and driving method thereof. The LED emitting device controls an LED drive switch connected to a first end of an LED string to control an output current supplied to the LED string. The LED emitting device generates feedback information on the output voltage or the output current supplied to the LED string, and uses the output current to sense an open lamp state of the LED string. The LED emitting device uses a voltage at a first end of the LED drive switch to sense a change of the LED string to a normal state from the open lamp state.

LED emitting device and driving method thereof

The present invention relates to an LED light emitting device and a driving method thereof. The LED light emitting device supplies a power supply voltage to at least two LED channels. The LED light emitting device samples channel voltages of the at least two LED channels to detect a minimum voltage from among the sampled voltages, and amplifies a difference between the detected minimum voltage and a predetermined reference voltage to generate an error amplifying signal. The LED light emitting device generates an enable signal having a duty extended by a predetermined delay period from a duty of a dimming signal for controlling light emission periods of the at least two LED channels. In this instance, the error generator is operable by the enable signal.

The present invention relates to an LED emitting device. The LED emitting device includes: a converter converting an input voltage according to a switching operation of a power source switch to generate at least two output voltages; an LED panel unit including a plurality of LED channels having a plurality of LEDs; a micom board operated by a first output voltage among the at least two output voltages to control the operation of the LED emitting device; a regulator converting a second output voltage among the at least two output voltages into a voltage suitable for the operation of the LED panel unit; and a multi-channel control unit controlling an operation of the regulator according to a lowest minimum voltage among the voltages of a plurality of LED channels and receiving the first output voltage to generate a first feedback voltage VF

LED emitting device

The present invention relates to an LED emitting device and a driving method thereof including at least two LED channels. If a power source voltage supplied to an LED emitting device reaches a predetermined threshold voltage, the power source voltage is maintained as a threshold voltage during an overvoltage regulation period.

An LED light emitting device includes LED channels with LEDs, a transformer that converts an input voltage and supply an output voltage to the LED channels, a controller, and an LED driver. The controller controls the transformer according to a first feedback signal for interrupting power supply to the LED channels when a dimming off state in which currents are not supplied to the plurality of LED channels occurs or when a state in which the maximum channel voltage of a plurality of channel voltages corresponding to voltages applied to the LED channels, respectively, is an overvoltage and a defective state in which the plurality of LED channels include an open state are maintained during a predetermined threshold period. The LED driver generates information on the dimming off state and information on the defective state.

LED light emitting device

Growing community of inventors

Seoul, South Korea

Byunghak Ahn