Samsung Electronics Co., Ltd.

Bongjin Lee

June Hyun Jang

Changseob Kim

A light-emitting diode (LED) control unit includes: a pulse generator configured to generate a pulse signal; a T-filter configured to convert the pulse signal into a triangular wave signal; a first gate driver configured to receive the triangular wave signal and output a first gate control signal; a second gate driver configured to receive the first gate control signal and output a second gate control signal; a first switch configured to turn on a first LED string corresponding to a first color temperature based on the first gate control signal; a second switch configured to turn on a second LED string corresponding to a second color temperature based on the second gate control signal; and a power supply circuit configured to supply a power supply voltage to the pulse generator, the first gate driver, and the second gate driver by stepping down an operating voltage of the LED driver.

LED control unit, lighting device having the same, and operating method thereof

A light emitting diode (LED) control device includes a power supply connected to a first driving node and a second driving node through which an LED driver is configured to supply power to an LED module including a first LED string and a second LED string, a square wave generator that generates a square wave, a duty ratio controller that outputs a control signal based on the square wave, and change a slope of the control signal based on a change in a time constant, and a switch circuit configured to control a ratio of a first current applied to the first LED string and a second current applied to the second LED string based on a change in the slope of the control signal.

LED control device and lighting device including the same

A light emitting diode (LED) device is provided. The LED device a first LED string configured to emit light having a first color temperature; a second LED string connected to the first LED string in parallel, and configured to emit light having a second color temperature different from the first color temperature; a controller configured to generate a control signal based on a control command received from an external controller; a switching circuit configured to control brightness of any one or any combination of the first LED string and the second LED string based on the control signal; and a power supply configured to generate an internal power voltage for operation of the controller and the switching circuit.

LED device and lighting device including the same

A light emitting diode (LED) control device includes: a power supply connected to a first driving node and a second driving node of an LED driver configured to provide driving power to a light source including a plurality of LEDs; a controller configured to operate by a first internal power voltage output from the power supply, and receive a control command from an external controller; and a switching device connected to the second driving node, and configured to operate by a second internal power voltage output from the power supply and control brightness of the light source based on a control signal which is output from the controller in response to the control command.

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Hwaseong-si, South Korea

Bongjin Lee