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: 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: A backlight unit for synchronization with an image signal for a liquid crystal display (LCD), which can synchronize frequencies of a lamp driving signal and a lamp brightness signal with frequencies of a horizontal synchronization signal and a vertical synchronization signal, which are image signals used in an LCD panel. The backlight unit includes a synchronization part generating a first synchronized signal synchronized with a horizontal synchronization signal having a preset frequency, and a second synchronized signal synchronized with a vertical synchronization signal having a frequency different from the frequency of the horizontal synchronization signal, and a signal generation part generating a lamp driving signal for driving a lamp according to the first synchronized signal and a lamp brightness signal for controlling brightness of the lamp according to the second synchronized signal.

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: 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. A frequency-variable oscillator according to an aspect of the invention includes: a voltage-to-current converter circuit converting a voltage level of an input signal into a current level within a predetermined range; and an oscillator circuit varying a frequency according to the current level from the voltage-to-current converter circuit and oscillating the varied frequency.

Abstract: A DC-AC converter has two half-bridge circuits using an input feedback signal and an input clock signal together with time delay circuits, wherein one of the half-bridge circuits drives one pair of corresponding FETs and the other half-bridge circuit drives the other pair of corresponding FETs. The DC-AC converter includes: a Direct Current (DC) power source; a switching unit which includes a plurality of Field Effect Transistors (FETs) for changing paths of Direct Current (DC), so as to convert the DC to Alternating Current (AC); a transformer for transforming a voltage input from the switching unit; a load unit connected to the transformer; and a signal control unit for simultaneous parallel control of the FETs in the switching unit.

Abstract: A DC-AC converter has two half-bridge circuits using an input feedback signal and an input clock signal together with time delay circuits, wherein one of the half-bridge circuits drives one pair of corresponding FETs and the other half-bridge circuit drives the other pair of corresponding FETs. The DC-AC converter includes: a Direct Current (DC) power source; a switching unit which includes a plurality of Field Effect Transistors (FETs) for changing paths of Direct Current (DC), so as to convert the DC to Alternating Current (AC); a transformer for transforming a voltage input from the switching unit; a load unit connected to the transformer; and a signal control unit for simultaneously parallel control of the FETs in the switching unit.