Abstract: The present invention relates to a dimming control device, an LED driving device, and a dimming control method. In accordance with an embodiment of the present invention, a dimming control device including: a PWM signal generating unit for generating a PWM signal from a reference signal and an input voltage; a signal compensating unit for compensating the PWM signal output from the PWM signal generating unit using an internal clock signal; and a synchronization unit for synchronizing the compensated signal with an external clock signal to output a synchronized PWM control signal for dimming control is proposed. Further, an LED driving device and a dimming control method are proposed.

Abstract: There is provided a light emitting diode (LED) driver removing signal interference by varying a switching frequency within a preset range. The LED driver includes a power supply section switching input power and supplying driving power to at least one LED; a switching control section controlling the switching of the power supply section according to a clock signal being supplied; and a clock signal generation section supplying the clock signal having a preset variable frequency range to the switching control section.

Abstract: Disclosed herein is a light emitting diode (LED) driving device for driving a multi-channel LED element or an LED array for each channel, the LED driving device including: a constant current driver driving currents flowing in each channel; a first switching unit selectively feeding-back voltage levels of each channel; and a switching controller controlling the turn on/off of the first switching unit, wherein matching characteristics of currents flowing in each channel is improved and a size of an integrated circuit (IC) chip is also reduced as compared to a case according to the related art, thereby making it possible to reduce a production cost and satisfy the trend of miniaturization of the chip, while solving a performance deterioration problem due to degradation of the matching of the currents between the channels.

Abstract: Disclosed herein is a light emitting diode (LED) driving device for driving a multi-channel LED element or an LED array for each channel, the LED driving device including: a constant current driver driving currents flowing in each channel; and a minimum voltage selector receiving voltage levels of each channel and selecting a minimum voltage level to thereby feedback the selected minimum voltage level to the constant current driver, wherein matching characteristics of currents flowing in each channel is improved and a size of an integrated circuit (IC) chip is also reduced as compared to a case according to the related art, thereby making it possible to reduce a production cost and satisfy the trend of miniaturization of the chip, while solving a performance deterioration problem due to deterioration of the matching of the currents between the channels.

Abstract: There is provided a digital PWM generator according to a first exemplary embodiment of the present invention including: an A/D converter dividing a predetermined reference voltage into a plurality of sections corresponding to a predetermined first set value, searching a section to which the magnitude of an input voltage Vin corresponds, among the plurality of sections, and converting a value corresponding to the searched section into a digital signal; a frequency selector providing a counting number by counting a predetermined high-speed counting clock during a one-cycle section of a predetermined reference clock; and a PWM signal generator converting the digital signal from the A/D converter into a ratio value corresponding to a ratio for the reference voltage and generating a PWM signal having a controlled duty ratio of the reference clock by using the ratio value and the counting number from the frequency selector.

Abstract: A driver for display provides a driving signal having a frequency synchronized with that of an image signal when the image signal is normal and provides a driving signal having a predetermined frequency when the image signal is abnormal, thereby performing a stable operation. The driver includes a frequency detection unit detecting a frequency difference between a frequency of an inputted image signal and a frequency of a frequency-divided driving signal, a driving signal generation unit generating the driving signal having a frequency synchronized with the frequency of the image signal according to a detection result of the frequency detection unit, and a control unit stopping a frequency detection operation of the frequency detection unit when the detection result of the frequency detection unit shows an abnormal operation.

Abstract: There is provided a driver for light emitting diodes capable of differently setting duties in which driving current flows depending on respective light emitting diode (LED) channels according to a voltage deviation between the LED channels in order to reduce heat generated due to the voltage deviation between the LED channels. The driver for LEDs includes: a detecting unit detecting a voltage drop generated in each of a plurality of LED channels receiving driving power having a preset voltage level; a converting unit converting detected analog values from the detecting unit into digital values; and a driving unit differently setting switching duties in which driving current flows in each of the plurality of LED channels according to the digital values from the converting unit to drive the plurality of LED channels.

Abstract: The device for generating three mode signals includes: a voltage setting block including an input terminal receiving three input signals of driving voltage, open, and ground and setting three voltages according to the three input signals; and an output block including two output terminals and a second node B receiving the three voltages from the voltage setting block, and outputting three combined signals by comparing an input voltage with a reference voltage, whereby only a small number of resistors and amplifiers generates three mode signals to further reduce the chip size than the related art and the external power source is not required to solve the problems of the related art due to noise.

Abstract: Disclosed herein is a device for controlling current of an LED including a constant current generator, a current mirror, and a current amplifier, the device controlling current of an LED, comprising: a selector outputting an L signal or an H signal according to an input control signal; and a current changing unit formed by connecting at least one switching unit in parallel, the switching unit including a transistor and a switch connected to the transistor in series. The device for controlling current of an LED adjusts current supplied to the current amplifier using a SEL input without an effect of a noise, thereby making it possible to change the current of the LED without separately changing a resistor.

Abstract: The present invention provides a module for controlling an LED current for selective feedback, an apparatus and a method for driving LEDs using the same. The module for controlling the LED current, which is connected to a plurality of LED channels receiving driving powers supplied from at least one DC/DC converter and controls currents of the LED channels through a constant current, the LED current controlling module includes: an operation mode selector for selecting an operation mode according to an inputted enable signal level; a channel divider for dividing a plurality of LED channels into at least one group according to the selected operation mode; and a minimum voltage selector for selecting an LED channel with a minimum voltage, obtained by comparing voltages detected from each of lower ends of the LED channels included in each of one or more divided groups.

Abstract: There is provided a light emitting diode (LED) driver removing signal interference by varying a switching frequency within a preset range. The LED driver includes a power supply section switching input power and supplying driving power to at least one LED; a switching control section controlling the switching of the power supply section according to a clock signal being supplied; and a clock signal generation section supplying the clock signal having a preset variable frequency range to the switching control section.

Abstract: An apparatus for driving a light emitting device (LED) is provided. The apparatus for driving the LED includes a first driving control element, a first current detection unit, a first effective value detection unit, a first reference signal generation unit, and a first comparison unit. The first driving control element controls a current flowing through a first LED channel, in response to a first pulse-width modulated control signal. The first current detection unit detects the current flowing through the first LED channel. The first effective value detection unit detects an effective value of the current detected by the first current detection unit. The first reference signal generation unit generates a preset reference signal having a sawtooth waveform. The first comparison unit compares the reference signal from the first reference signal generation unit with the effective value from the first effective value detection unit.

Abstract: Provided is an apparatus for driving a light emitting element. The apparatus includes a power unit, a light emitting element array, a constant-current circuit unit, and a voltage limiting circuit unit. The power unit supplies driving power. The light emitting element array includes a plurality of light emitting elements connected in series between an anode terminal connected to the power unit and a cathode terminal. The constant-current circuit unit maintains a constant current flowing through the light emitting element array according to a first tuning voltage. The voltage limiting circuit unit is connected between the cathode terminal of the light emitting element array and the constant-current circuit unit, and divides a total voltage applied between the cathode terminal of the light emitting element array and a ground according to a second tuning voltage to limit a voltage applied to the constant-current circuit unit below a predetermined voltage.

Abstract: There is provided a frequency-variable oscillator that varies, even when a frequency of an input signal is varied, a frequency of an oscillation signal according to the varied frequency of the input signal. The frequency-variable oscillator includes: a voltage-to-current converter circuit for converting a voltage level of an input signal into a current level within a predetermined range; and an oscillator circuit for varying a frequency according to the current level from the voltage-to-current converter circuit and oscillating the varied frequency.

Abstract: The present invention provides a module for controlling an LED current for selective feedback, an apparatus and a method for driving LEDs using the same. The module for controlling the LED current, which is connected to a plurality of LED channels receiving driving powers supplied from at least one DC/DC converter and controls currents of the LED channels through a constant current, the LED current controlling module includes: an operation mode selector for selecting an operation mode according to an inputted enable signal level; a channel divider for dividing a plurality of LED channels into at least one group according to the selected operation mode; and a minimum voltage selector for selecting an LED channel with a minimum voltage, obtained by comparing voltages detected from each of lower ends of the LED channels included in each of one or more divided groups.

Abstract: An inverter driver integrated circuit (IC) includes a control signal generator generating a first control signal and a second control signal by use of a pulse width modulation oscillator signal, a comparator comparing a half-wave rectified signal of a lamp feedback signal fed back from a lamp with a preset reference signal to output a lamp state signal, a first sensor receiving the lamp state signal and the second control signal to output a first sensing signal, and a second sensor receiving the first sensing signal and the first control signal to output a second sensing signal.

Abstract: There is provided a frequency-variable oscillator that varies, even when a frequency of an input signal is varied, a frequency of an oscillation signal according to the varied frequency of the input signal. The frequency-variable oscillator includes: a voltage-to-current converter circuit for converting a voltage level of an input signal into a current level within a predetermined range; and an oscillator circuit for varying a frequency according to the current level from the voltage-to-current converter circuit and oscillating the varied frequency.

Abstract: There is provided a phase detection apparatus that can accurately detect a phase difference between an input signal and a reference signal even when the input signal and the reference signal have different duty cycles. A phase detection apparatus according to an aspect of the invention may include: a pulse generation unit generating a first pulse signal on an edge of an input pulse signal, and a second pulse signal based on an edge of a reference pulse signal having a predetermined phase; and a detection unit detecting a phase difference between the first pulse signal and the second pulse signal from the pulse generation unit.

Abstract: An inverter driver integrated circuit (IC) includes a control signal generator generating a first control signal and a second control signal by use of a pulse width modulation oscillator signal, a comparator comparing a half-wave rectified signal of a lamp feedback signal fed back from a lamp with a preset reference signal to output a lamp state signal, a first sensor receiving the lamp state signal and the second control signal to output a first sensing signal, and a second sensor receiving the first sensing signal and the first control signal to output a second sensing signal.

Abstract: A driver for display provides a driving signal having a frequency synchronized with that of an image signal when the image signal is normal and provides a driving signal having a predetermined frequency when the image signal is abnormal, thereby performing a stable operation. The driver includes a frequency detection unit detecting a frequency difference between a frequency of an inputted image signal and a frequency of a frequency-divided driving signal, a driving signal generation unit generating the driving signal having a frequency synchronized with the frequency of the image signal according to a detection result of the frequency detection unit, and a control unit stopping a frequency detection operation of the frequency detection unit when the detection result of the frequency detection unit shows an abnormal operation.