Abstract: A driving circuit for a light emitting diode connected to a TRIAC dimmer configured to modulate an input AC voltage depending on a selected dimming level including a rectifier configured to full-wave rectify the modulated AC voltage output from the TRIAC dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level and drive a plurality of light emitting diode groups depending on the detected dimming level, and a bleeder circuit configured to provide a bleeder current to the TRIAC dimmer, in which the bleeder circuit is configured to provide the bleeder current only for a preset on-duty time.

Abstract: A lighting apparatus including a light emitting diode connected to a dimmer configured to modulate an input AC voltage depending on a selected dimming level, a rectifier configured to full-wave rectify the modulated AC voltage output from the dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level, and select one of three driving modes of a stop mode, a resistance driving mode, and a sequential driving mode depending on the detected dimming level, and a plurality of light emitting diode groups configured to emit light depending on a control of the driving module.

Abstract: A driving circuit for a light emitting diode connected to a TRIAC dimmer configured to modulate an input AC voltage depending on a selected dimming level including a rectifier configured to full-wave rectify the modulated AC voltage output from the TRIAC dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level and drive a plurality of light emitting diode groups depending on the detected dimming level, and a bleeder circuit configured to provide a bleeder current to the TRIAC dimmer, in which the bleeder circuit is configured to provide the bleeder current only for a preset on-duty time.

Abstract: A lighting apparatus including a light emitting diode connected to a dimmer configured to modulate an input AC voltage depending on a selected dimming level, a rectifier configured to full-wave rectify the modulated AC voltage output from the dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level, and select one of three driving modes of a stop mode, a resistance driving mode, and a sequential driving mode depending on the detected dimming level, and a plurality of light emitting diode groups configured to emit light depending on a control of the driving module.

Abstract: Disclosed herein are a driving circuit and a lighting apparatus for a light emitting diode capable of improving a flicker, light efficiency, and electrical characteristics. The disclosed driving circuit for a light emitting diode includes: a dimmer modulating an AC voltage input depending on a selected dimming level; a rectifier full-wave rectifying the modulated AC voltage output from the dimmer to generate and output a driving voltage; and a driving module receiving the driving voltage of the rectifier to detect the selected dimming level and controlling a driving mode of a plurality of light emitting diode groups depending on the detected dimming level, in which the driving module selects one of a resistance driving mode driving all the plurality of light emitting diode groups and a sequential driving mode sequentially driving the plurality of light emitting diode groups to improve light efficiency and electrical characteristics.

Abstract: A light-emitting diode (LED) driving circuit configured to drive LED units includes a rectification circuit unit to receive an alternating current (AC) power voltage and rectify the AC power voltage to output a unidirectional ripple voltage, a pulse-width modulation (PWM) signal generation unit to generate PWM decision signals. The PWM signal generation unit is configured to sequentially drive the LEDs according to the PWM decision signals.

Abstract: Disclosed herein are a driving circuit and a lighting apparatus for a light emitting diode capable of improving a flicker, light efficiency, and electrical characteristics. The disclosed driving circuit for a light emitting diode includes: a dimmer modulating an AC voltage input depending on a selected dimming level; a rectifier full-wave rectifying the modulated AC voltage output from the dimmer to generate and output a driving voltage; and a driving module receiving the driving voltage of the rectifier to detect the selected dimming level and controlling a driving mode of a plurality of light emitting diode groups depending on the detected dimming level, in which the driving module selects one of a resistance driving mode driving all the plurality of light emitting diode groups and a sequential driving mode sequentially driving the plurality of light emitting diode groups to improve light efficiency and electrical characteristics.

Abstract: An LED driving circuit package includes a rectification unit to receive an AC power voltage and rectify the AC power voltage to generate a ripple voltage, an LED driving switching unit including a plurality of switch units and a plurality of current control units. The LED driving circuit package further includes a low voltage control unit including a circuit power supply unit to generate low voltage power, a voltage detection unit to detect a magnitude of the ripple voltage, a reference frequency generation unit to generate a reference frequency, and a reference pulse generation unit to generate a reference pulse for controlling the operation of the LED driving switch unit according to the reference frequency and a magnitude of the voltage detected by the voltage detection unit.

Abstract: A vertical gallium nitride transistor according to an exemplary embodiment of the present invention includes a semiconductor structure including a first semiconductor layer of a first conductivity-type having a first surface and sidewalls, a second semiconductor layer of the first conductivity-type surrounding the first surface and the sidewalls of the first semiconductor layer, and a third semiconductor layer of a second conductivity-type disposed between the first semiconductor layer and the second semiconductor layer, the third semiconductor layer separating the first and second semiconductor layers from each other.

Abstract: Disclosed are a group III-V based transistor and a method for manufacturing same. The group III-V based transistor includes a laminated semiconductor structure having an upper surface and a lower surface and including a group III-V based semiconductor layer, and at least one 2DEG region extending from the upper surface of the laminated semiconductor structure to the lower surface thereof. A vertical-type GaN-based transistor using 2DEG can be provided by adopting the 2DEG region.

Abstract: A light-emitting diode (LED) driving circuit configured to drive LED units includes a rectification circuit unit to receive an alternating current (AC) power voltage and rectify the AC power voltage to output a unidirectional ripple voltage, a pulse-width modulation (PWM) signal generation unit to generate PWM decision signals. The PWM signal generation unit is configured to sequentially drive the LEDs according to the PWM decision signals.

Abstract: Exemplary embodiments of the present invention disclose a unidirectional heterojunction transistor including a channel layer made of a first nitride-based semiconductor having a first energy bandgap, a barrier layer made of a second nitride-based semiconductor having a second energy bandgap different from the first energy bandgap, the barrier layer including a recess, a drain electrode disposed on a first region of the barrier layer, and a recessed-drain Schottky electrode disposed in the recess of the barrier layer, the recessed-drain Schottky electrode contacting the drain electrode.

Abstract: An LED luminescence apparatus includes a plurality of LED units connected in series which are configured to receive a unidirectional ripple voltage, a plurality of switch units, one end of each being connected to the cathode of one of the plurality of LED units, a plurality of constant current control circuit units, one end of each being connected to an another end of a respective switch unit to receive a current from the respective switch unit, each of the constant current control circuit units being configured to output a current control signal to the respective switch unit to control a magnitude of the received current to have a specific value, and a current comparison unit to receive currents flowing from the plurality of switching units, and generate a plurality of switching control signals for the respective switch units to sequentially drive the plurality of constant current control circuit units.

Abstract: Exemplary embodiments of the present invention disclose a heterojunction transistor having a normally off characteristic using a gate recess structure and a method of fabricating the same. The heterojunction transistor may include a substrate, a channel layer disposed on the substrate and made of a first nitride-based semiconductor having a first energy bandgap, a first barrier layer disposed on the channel layer and made of a second nitride-based semiconductor having a second energy bandgap different from the first energy bandgap, a gate electrode disposed in a gate control region of the first barrier layer, and a second barrier layer disposed in gate non-control regions of the first barrier layer and separated from the first barrier layer.

Abstract: Exemplary embodiments of the present invention disclose a unidirectional heterojunction transistor including a channel layer made of a first nitride-based semiconductor having a first energy bandgap, a barrier layer made of a second nitride-based semiconductor having a second energy bandgap different from the first energy bandgap, the barrier layer including a recess, a drain electrode disposed on a first region of the barrier layer, and a recessed-drain Schottky electrode disposed in the recess of the barrier layer, the recessed-drain Schottky electrode contacting the drain electrode.

Abstract: A vertical gallium nitride transistor according to an exemplary embodiment of the present invention includes a semiconductor structure including a first semiconductor layer of a first conductivity-type having a first surface and sidewalls, a second semiconductor layer of the first conductivity-type surrounding the first surface and the sidewalls of the first semiconductor layer, and a third semiconductor layer of a second conductivity-type disposed between the first semiconductor layer and the second semiconductor layer, the third semiconductor layer separating the first and second semiconductor layers from each other.

Abstract: A light-emitting diode (LED) luminescence apparatus configured to receive an alternating current (AC) power includes a plurality of LED units, and a plurality of constant current control units electrically connected to the plurality of LED units. The current control units are configured to control current flowing through each of the LED units so that the current has a specific magnitude.

Abstract: An LED driving circuit package includes a rectification unit to receive an AC power voltage and rectify the AC power voltage to generate a ripple voltage, an LED driving switching unit including a plurality of switch units and a plurality of current control units. The LED driving circuit package further includes a low voltage control unit including a circuit power supply unit to generate low voltage power, a voltage detection unit to detect a magnitude of the ripple voltage, a reference frequency generation unit to generate a reference frequency, and a reference pulse generation unit to generate a reference pulse for controlling the operation of the LED driving switch unit according to the reference frequency and a magnitude of the voltage detected by the voltage detection unit.

Abstract: An LED luminescence apparatus includes a plurality of LED units connected in series which are configured to receive a unidirectional ripple voltage, a plurality of switch units, one end of each being connected to the cathode of one of the plurality of LED units, a plurality of constant current control circuit units, one end of each being connected to an another end of a respective switch unit to receive a current from the respective switch unit, each of the constant current control circuit units being configured to output a current control signal to the respective switch unit to control a magnitude of the received current to have a specific value, and a current comparison unit to receive currents flowing from the plurality of switching units, and generate a plurality of switching control signals for the respective switch units to sequentially drive the plurality of constant current control circuit units.