Abstract: There is provided an LED circuit. The LED circuit may include 2N+2 light emitting units connected between a 2K?1-th node and a 2K-th node among 4N+4 (N is a natural number) nodes including a first node supplied with input voltage (K is all natural numbers equal to or smaller than 2N+2); 2N+2 switches connected between a 2K-th node and a ground (K is all natural numbers equal to or smaller than 2N+2); 2N+1 switches connected between a 2L?1-th node and a 2L+1-th node and 2N+1 switches connected between a 2L-th node and a 2L+1-th node (L is all natural numbers equal to or smaller than 2N+1); and N switches connected between the first node and a 4M+1-th node (M is all natural numbers equal to or smaller than N).

Abstract: There is provided an apparatus for driving a light emitting diode (LED), capable of distributing current stress applied to the LED. The apparatus includes an LED part including a plurality of LED units respectively including at least one LED, the plurality of LED units being connected in parallel to a power input terminal to which rectified power in sine wave form is supplied, and, among the plurality of LED units connected in parallel, a termination end of the LED unit in a front end being connected to a middle of an adjacent LED unit; and a current source unit including a plurality of current sources respectively connected to termination ends of the plurality of LED units and allowing corresponding current to flow through the plurality of LED units.

Abstract: There is provided an illumination driving apparatus for a light emitting diode, the apparatus including: a light emitting unit including M number of light emitting diodes (LEDs) connected in series and driven by an output voltage rectified in a rectifying unit; an LED switch unit including N number of LED switches connected in parallel with at least N number of the M LEDs, respectively, and connected in series; an LED switch control signal generating unit comparing the output voltage of the rectifying unit with each of the first to Nth preset reference voltages to generate N number of LED switch control signals controlling the LED switch unit; and an LED switch controlling unit transferring the N number of LED switch control signals to the LED switch unit.

Abstract: There is provided a light emitting diode driving apparatus capable of supplying a constant average current to a light emitting diode by generating a reference voltage used for driving the light emitting diode according to input power and a switching signal switching a path of a current supplied to the light emitting diode. The light emitting diode driving apparatus includes: a reference voltage generating unit generating a reference voltage set based on input power and a switching signal for supplying driving power to a light emitting diode; and a driving unit supplying the driving power to the light emitting diode according to the reference voltage.

Abstract: Provided is a PWM control circuit for a DC-DC converter, flyback converter and a method of controlling a PWM of a DC-DC converter. The PWM control circuit for the DC-DC converter includes a current sensing unit configured to sense a primary-side current, a zero-current detecting unit configured to detect a zero-current from a secondary-side auxiliary winding, a time calculating unit configured to receive a main switch control signal and an output signal of the zero-current detecting unit to calculate a time from an OFF point of a main switch to a point that the secondary-side current becomes zero, and a control unit configured to receive an output signal of the current sensing unit and time information produced by the time calculating unit to calculate a secondary-side output voltage and perform PWM control with respect to the main switch according to the calculated secondary-side output voltage.

Abstract: Disclosed herein are a circuit and a method for driving LED light. There is provided a circuit for driving LED light, including: a dimming block comparing line voltage supplied to the LED light with reference voltage to output a peak value of voltage charged according to a comparison signal as a first reference signal; a reference signal generation block comparing the first reference signal output from the dimming block with a peak value of sensing voltage sensing current of an LED driving switch to amplify an error and multiplying the line voltage by the error amplified signal so as to be output as a second reference signal; and a PWM control block comparing the second reference signal output from the reference signal generation block with the sensing voltage to output a PWM signal with controlled duty. In addition, a method for driving LED light is proposed.

Abstract: There is provided a light emitting diode driving apparatus for controlling the light emitting diode driving according to a feedback signal input through a positive feedback loop, the light emitting diode driving apparatus including: a power converting unit switching input power and supplying driving power to at least one light emitting diode; a feedback unit detecting and feeding back a voltage of the driving power of the power converting unit; and a controlling unit including a comparator having a negative terminal receiving a reference voltage having a set voltage level and a positive terminal receiving the detected voltage from the feedback unit and comparing the reference voltage with the detected voltage to control a switching of the power converting unit according to a comparison result.

Abstract: Provided is a circuit, a device and a method of direct-driving an LED. According to an embodiment, the LED direct-driving circuit includes an LED unit having a plurality of LED groups serially connected to each other, a switching unit including a plurality of switches respectively connected to the plurality of LED groups, each switch configured to emit light from at least one LED group serially connected to the switch according to an ON operation, and a switching control unit configured to compare a signal according to a line voltage sensed from an input voltage of the LED unit with an output voltage of the LED unit to calculate a comparison value, generate a PWM carrier signal having a frequency varied according to the line voltage, and output a control signal for controlling the switching unit by comparing the comparison value with the frequency-varied PWM carrier signal.

Abstract: There is provided a light emitting diode driving apparatus satisfying regulations for current transferred to a light emitting diode. The light emitting diode driving apparatus includes: a power supplying unit receiving input power to convert the input power into a preset driving power and supplying the driving power to a light emitting diode unit including at least one light emitting diode; a detecting unit receiving the driving power supplied to the light emitting diode unit to detect voltage flowing in the light emitting diode unit; a controlling unit comparing detection voltage detected by the detecting unit with a preset reference voltage to control a power conversion operation of the power supplying unit; and a driving unit driving the power conversion operation according to controlling by the controlling unit.

Abstract: There is provided a driving apparatus for a light emitting diode (LED) comparing a rectified power voltage level with an LED current to limit current applied to an LED, thereby reducing the amount of heat generated therein. The driving apparatus for an LED includes a detecting unit detecting a voltage level of rectified power; and a driving unit comparing a level of current flowing in an LED unit having at least one LED with detection results from the detecting unit, and limiting current applied to the LED unit to drive the LED unit according to comparison results.

Abstract: There is provided an organic light emitting diode driver capable of compensating for pixel deterioration in real time during the driving of pixels by selectively compensating pixels, requiring compensation, for the deterioration thereof, and precisely setting calibration data by removing an IR drop across a transistor, employed as a switch in the pixels, by calculating a difference between at least two representative values of different gray scale ranges among predetermined gray scale ranges.

Abstract: There are provided a driving apparatus for a light emitting diode (LED) which may accurately display a desired color of light by adjusting a color coordinate value in accordance with an input brightness value, and a control method thereof. The driving apparatus includes a control unit receiving a brightness value and a color coordinate value of an LED desired to be controlled and controlling LED driving by adjusting the color coordinate value in accordance with the received brightness value; and a driving unit driving the LED in accordance with controlling of the control unit.

Abstract: Disclosed herein is a light emitting diode (LED) driving apparatus including: at least one energy storages connected in series with each other; a plurality of LEDs each connected in parallel with each of the energy storages; and a switching control unit selectively connecting the at least one energy storages according to a level of applied voltage to charge/discharge voltage in/from the selected energy storages and control driving of the LEDs by the charging/discharging operation. Therefore, it is possible to easily drive the LEDs without a converter.

Abstract: There are provided a light emitting diode (LED) driving device allowing for an increase in an LED driving rate by discharging a charge stored in a capacitor during a certain period of time and a method thereof. The LED driving device includes: a driving unit detecting a current, as a voltage, the current flowing across an LED unit having at least one LED, controlling the current flowing across the LED unit according to a comparison result between the detected voltage and a reference voltage having a pre-set voltage level, and having a capacitor stabilizing an operation of the LED unit when the LED unit is driven; and a discharging unit discharging a charge stored in the capacitor during a pre-set discharge time when the LED unit is initially driven.

Abstract: There is provided a light emitting diode (LED) driver having an offset voltage compensating function compensating for an offset voltage generated at the time of driving of an LED, the LED driver including: a driving unit detecting a current flowing in an LED unit having at least one LED, as a voltage and controlling the current flowing in the LED unit according to a comparison result between the detected voltage and a reference voltage having a preset voltage level; and an offset compensating unit integrating a voltage difference between the detected voltage and the reference voltage and adding or subtracting a compensating current according to an integration result to thereby compensate for an offset.

Abstract: There are provided an LED driving apparatus and an LED driving method thereof. The LED driving apparatus includes: a light emitting unit including one or more LEDs, a rectifying unit rectifying an input signal to generate a first signal; a signal conversion unit inverting a waveform of a first signal to generate a second signal; and an operation unit arithmetically operating the first and second signals. A plurality of AC signals each having a different waveform are arithmetically operated to generate a signal having a small amount of a ripple component, and an LED is driven by the signal, thus preventing a lifespan of the LED from being shortened by omitting a smoothing electrolytic capacitor, one of main causes shortening the lifespan of an LED driving circuit.

Abstract: There is provided an LED circuit. The LED circuit may include 2N+2 light emitting units connected between a 2K?1-th node and a 2K-th node among 4N+4 (N is a natural number) nodes including a first node supplied with input voltage (K is all natural numbers equal to or smaller than 2N+2); 2N+2 switches connected between a 2K-th node and a ground (K is all natural numbers equal to or smaller than 2N+2); 2N+1 switches connected between a 2L?1-th node and a 2L+1-th node and 2N+1 switches connected between a 2L-th node and a 2L+1-th node (L is all natural numbers equal to or smaller than 2N+1); and N switches connected between the first node and a 4M+1-th node (M is all natural numbers equal to or smaller than N).

Abstract: There is provided an LED circuit including a light emitting unit including a plurality of light emitting diodes; and a switching unit switching to apply only positive voltage of an AC power supply to an anode of the light emitting unit. Through this, the LED circuit can reduce complexity of a driving circuit. Further, lifespan and efficiency of the LED circuit may be improved since an electrolytic capacitor and a bridge circuit are not used. Further, any one light emitting diode may be prevented from determining the lifespan of all of the light emitting diodes since all of the light emitting diodes are driven at all times, thereby improving the lifespan of the light emitting diode.

Abstract: There is provided an active matrix organic light emitting diode (AMOLED) display including a driver generating analog driving signals based on previously prepared driving data; a pixel unit including an organic light emitting diode connected between first and second power supply terminals receiving first and second power, respectively, charging values equivalent to the driving data according to the driving signals and simultaneously detecting the driving signals in order to detect deterioration in a preset tracking period, allowing current to flow through the organic light emitting diode according to the values charged in the tracking period in a preset holding period, and setting a reset period between the holding period and a tracking period subsequent thereto to reset the charged values; and an ADC detecting a deterioration voltage corresponding to the driving signals having deterioration information of the organic light emitting diode of the pixel unit in the tracking period.

Abstract: There is provided an organic light emitting diode driver capable of compensating for pixel deterioration in real time during the driving of pixels by selectively compensating pixels, requiring compensation, for the deterioration thereof. The organic light emitting diode driver includes: a converter converting input data into compensation data used to selectively compensate for pixel deterioration according to whether or no the input data has been calibrated; a driver driving pixels of a pixel unit according to the compensation data from the converter; and a compensator providing the converter with a deterioration compensation signal according to deterioration information obtained from a pixel driven by the driver.