Abstract: In an FSC mode LCD, a controller operates in response to an external adjustment, and a DC/DC converter converts a battery voltage into a driving voltage under control of the controller. A color LED backlight includes first, second and third color LED arrays connected in parallel, which are operated by the driving voltage. An FSC generator generates first, second and third color PWM signals according to an internal sawtooth voltage and a dimming voltage. A 3-channel current source generates first, second and third driving currents under control of the controller, and on/off switches paths of the first, second and third driving currents flowing through the first, second and third color LED arrays according to the first, second and third color PWM signals generated from the FSC generator, thereby adjusting luminance of the first, second and third color LED arrays of the color LED backlight.

Abstract: The present invention relates to a light emitting diode driver having a protection function that activates hiccup mode for a predetermined period of time when a light emitting diode performs an abnormal operation to thereby protect the light emitting diode. A light emitting diode driver having a protection function according to an aspect of the invention may include: a light emitting unit emitting light; a reference signal generating unit generating a reference signal having pulses with a predetermined period when the light emitting unit performs an abnormal operation; a control unit controlling operating time in hiccup mode according to the reference signal from the reference signal generating unit, the hiccup mode where output is switched on and off at a predetermined period; and a driving unit driving the light emitting unit in the hiccup mode for the operating time determined by the control unit.

Abstract: There is provided an LED driving circuit including: at least one ladder network circuit including: (n+1) number of first branches connected in parallel with one another by n number of first middle junction points between a first junction point and a second junction point, where n denotes an integer satisfying n?2, (n+1) number of second branches connected in parallel with one another by n number of second middle junction points between the first junction point and the second junction point, the (n+1) number of second branches connected in parallel with the first branches; and n number of middle branches connecting the first and second middle junction points of an identical m sequence to each other, respectively, wherein each of the first and second, and middle branches comprises at least one LED device.

Abstract: An apparatus for driving a light emitting device according to an aspect of the invention may include: a DC/DC converter unit generating driving power on the basis of an input voltage and supplying the generated driving power to an anode of a light emitting unit including a plurality of light emitting devices; a current source controlling to keep current flowing through the light emitting unit constant; a feedback circuit unit detecting voltage at a cathode of the light emitting unit; and a feedback coupling circuit unit coupling the output of the feedback circuit unit and the input of the DC/DC converter unit to supply the input voltage of the DC/DC converter unit according to the voltage detected by the feedback circuit unit and an output voltage of the DC/DC converter unit.

Abstract: An apparatus for driving multi-light emitting devices that drives a multi-channel light emitting unit having a plurality of light emitting channels connected in parallel with each other, each of which has a plurality of light emitting devices connected in series with each other according to an aspect of the invention may include: a DC/DC converter generating a driving voltage; a current control unit having a plurality of current sources connected between cathodes of the plurality of light emitting channels and a ground; a minimum voltage selection unit detecting a minimum detection voltage among the plurality of detected voltages at the cathodes of the plurality of light emitting channels; a first error detection unit detecting an error voltage determined by the difference between the minimum detection voltage and a predetermined first reference voltage; and a feedback coupling unit supplying the input voltage according to the error voltage and the driving voltage.

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 an LED driving circuit including: at least one ladder network circuit including: (n+1) number of first branches connected in parallel with one another by n number of first middle junction points between a first junction point and a second junction point, where n denotes an integer satisfying n?2, (n+1) number of second branches connected in parallel with one another by n number of second middle junction points between the first junction point and the second junction point, the (n+1) number of second branches connected in parallel with the first branches; and n number of middle branches connecting the first and second middle junction points of an identical m sequence to each other, respectively, wherein each of the first and second, and middle branches comprises at least one LED device.

Abstract: There is provided an LED driving circuit including: at least one ladder network circuit including: (n+1) number of first branches connected in parallel with one another by n number of first middle junction points between a first junction point and a second junction point, where n denotes an integer satisfying n?2, (n+1) number of second branches connected in parallel with one another by n number of second middle junction points between the first junction point and the second junction point, the (n+1) number of second branches connected in parallel with the first branches; and n number of middle branches connecting the first and second middle junction points of an identical m sequence to each other, respectively, wherein each of the first and second, and middle branches comprises at least one LED device.

Abstract: Disclosed is a liquid crystal display (LCD) backlight inverter. The LCD backlight inverter includes a lamp open detection unit outputting a first open detection voltage for a preset time period when it is determined that a predetermined lamp is open, based on a current voltage corresponding to the current of the predetermined lamp of a plurality of lamps, a first open determination unit outputting an open detection signal when the first open detection voltage is input, a second open determination unit outputting a protection signal when it is determined that all of the plurality of lamps are open based on detection voltages of the plurality of lamps, a temporary protection determination unit outputting a frequency change signal when both the open detection signal and the protection signal are input, and an operating frequency control unit changing an operating frequency to a preset protective frequency according to the frequency change.

Abstract: A dimming buck type light emitting diode (LED) driving apparatus includes a main switch controlling a driving current flowing into an LED; a current detector detecting a driving current flowing into the LED; a power level determination unit determining a level of the driving power; a dimming capacitor for dimming control; a dimming control unit controlling charging and discharging of the dimming capacitor according to a power level determination signal and an enable signal; a reset circuit unit generating a reset signal according to a detection voltage from the current detector and a voltage of the dimming capacitor; a pulse generation unit generating a pulse signal; and a latch set by the pulse signal of the pulse generation unit and reset by the reset signal of the reset circuit unit to generate a switching signal, and turning on and off the main switch using the switching signal.

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: 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: An inverter driving circuit for an LCD is switched on/off more stably to improve heating radiation characteristics and drive efficiency. In the driving circuit, a controller supplies a first driving signal. A level shifter provides a second driving signal. A first delay circuit delays a rising section of the first driving signal to provide the first driving signal. A second delay circuit delays a falling section of the second driving signal to provide the second driving signal. Also, a power switching circuit is provided. The inverter driving circuit for the LCD, when a switching device thereof is turned off, has less current flowing in the switching device, thereby generating less heat. In addition, the inverter driving circuit prevents heat generation caused by current flowing reversely in the switching device, thereby enhancing drive efficiency.

Abstract: In a time control circuit, a capacitor is connected between a connecting pin and a ground. A first current source supplies a first current to the connecting pin. A first comparator element has a non-inverse terminal connected to a voltage of the capacitor and a pre-set first reference voltage, and controls the initial startup time. A second comparator element has an inverse terminal connected to the voltage of the capacitor and a pre-set second reference voltage, and controls the soft start time. Further, a current bypass controller includes a current bypass path between the connecting pin and the ground, which connects the current bypass path after the soft start time and blocks it at an input of a protective signal. Additionally, a third comparator element has an inverse terminal connected to the voltage of the capacitor and a pre-set third reference voltage, and controls the shutdown time.

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: Disclosed herein is a drive device of a color light emitting diode (LED) backlight, which is capable of precisely adjusting the forward voltages of color LED arrays for each channel.

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 LCD backlight inverter includes a soft starter for generating a soft-start reference voltage gradually increasing as the driving power begins to be supplied. The LCD backlight inverter also includes a first error detector for receiving a first feedback voltage indicating the magnitude of driving current of the lamp and for comparing a smaller value out of a predetermined first reference voltage and the soft-start reference voltage with the first feedback voltage to generate a first error signal corresponding to the difference between the smaller value and the soft-start reference voltage. The LCD backlight inverter further includes a pulse width modulation comparator for comparing the first error signal and a triangle wave oscillation signal to output the pulse width modulation control signal with a predetermined duty ratio. The LCD backlight inverter prevents application of over-current and over-voltage to the LCD backlight to prolong the lifetime of the backlight.

Abstract: There is a provided a dual mode clock generator that is applicable to a direct current-direct current converter of a power supply. The dual mode clock generator includes a frequency controller for controlling generation of charge and discharge; a current source unit for generating a charge, and generating a charge; a capacitor for charging a voltage according to the charge current generated by the current source unit; an oscillation controller for controlling switch-on or switch-off to charge and discharge the capacitor; a switch for controlling the charging and discharging of the capacitor through the ON or OFF control of the oscillation controller; and a current sink unit for generating a discharge current according to the second current in the first operation mode and generating a discharge current according to the third current and the fourth current in the second operation mode.