Abstract: A light emitting diode driving device and a light emitting diode backlight module are provided. A current is provided to a filter circuit by a controllable current source controlled by a dimming signal, so that the filter circuit generates a corresponding dimming voltage to control current flowing through a LED unit to dim the LED unit.

Abstract: A light emitting diode driving device and a light emitting diode backlight module are provided. A current is provided to a filter circuit by a controllable current source controlled by a dimming signal, so that the filter circuit generates a corresponding dimming voltage to control current flowing through a LED unit to dim the LED unit.

Abstract: A power conversion apparatus including a power conversion circuit, a light-emitting unit and a control chip is provided. The control chip has a multi-function pin and a feedback pin, where the multi-function pin and the feedback pin respectively receive a dimming signal and a feedback signal reflecting an output current of the light-emitting unit, and the control chip determines whether to generate a PWM signal to a power switch of the power conversion circuit according to the dimming signal and the feedback signal based on a duty ratio of the dimming signal.

Abstract: A LED backlight module including a LED string and a driving apparatus is provided. The driving apparatus comprises a sensing resistor, an adjustable voltage-divider circuit, a comparator, a power converter and a control circuit. The sensing resistor is coupled between a cathode of the LED string and a ground potential and generates a feedback voltage. The adjustable voltage-divider circuit generates a reference voltage according to a dividing ratio which is controlled by a first signal set and a second signal set. The comparator compares the feedback voltage and the reference voltage, and generates a control signal accordingly. The power converter provides a DC voltage to an anode of the LED string according to the control signal. The control circuit counts a disable period of a dimming signal to generate the first signal set, and counts an enable period of the dimming signal to generate the second signal set.

Abstract: A light emitting diode (LED) driving apparatus and an LED backlight system using the same are provided. The backlight control circuit suitable for driving an LED string includes a complex function pin, a driving circuit and a backlight control circuit. The backlight control circuit includes a control current generating unit, a first current comparing unit and a second current comparing unit. The control current generating unit receives a dimming control signal and an enable control signal from the complex function pin to generate a control current accordingly. The first and the second current comparing units are respectively configured to compare the control current with first and second predetermined currents to respectively generate a first and a second control signals. The driving circuit determines to be turned on or off according to the second control signal, and further adjusts a luminance of the LED string according to the first control signal.

Abstract: A driving circuit with an over-voltage protection device for modulating an electrical parameter of a driven device includes at least a boost circuit, a signal processing circuit, an over-voltage protection device, a modulation device and a control circuit. The output terminal of the boost circuit is electrically coupled in series to a driven device, a transistor and a grounded feedback resistor sequentially, wherein the output terminal of the boost circuit is further electrically coupled to a voltage dividing circuit for outputting a voltage dividing signal. The signal processing circuit is provided for outputting a processing signal to the over-voltage protection device and the modulation device according to the voltage dividing signal and a modulation signal. The control circuit is provided for turning on the transistor or not according to an output signal of the over-voltage protection device and an output signal of the modulation device.

Abstract: A light emitting diode (LED) driving apparatus and an LED backlight system using the same are provided. The backlight control circuit suitable for driving an LED string includes a complex function pin, a driving circuit and a backlight control circuit. The backlight control circuit includes a control current generating unit, a first current comparing unit and a second current comparing unit. The control current generating unit receives a dimming control signal and an enable control signal from the complex function pin to generate a control current accordingly. The first and the second current comparing units are respectively configured to compare the control current with first and second predetermined currents to respectively generate a first and a second control signals. The driving circuit determines to be turned on or off according to the second control signal, and further adjusts a luminance of the LED string according to the first control signal.

Abstract: A driving circuit with an over-voltage protection device for modulating an electrical parameter of a driven device includes at least a boost circuit, a signal processing circuit, an over-voltage protection device, a modulation device and a control circuit. The output terminal of the boost circuit is electrically coupled in series to a driven device, a transistor and a grounded feedback resistor sequentially, wherein the output terminal of the boost circuit is further electrically coupled to a voltage dividing circuit for outputting a voltage dividing signal. The signal processing circuit is provided for outputting a processing signal to the over-voltage protection device and the modulation device according to the voltage dividing signal and a modulation signal. The control circuit is provided for turning on the transistor or not according to an output signal of the over-voltage protection device and an output signal of the modulation device.

Abstract: A light-emitting-diode (LED) driving apparatus is provided, and which includes a power switch having a first terminal coupled to a first node and a second terminal coupled to a second node, wherein an LED string is coupled between a DC voltage and the first node; a first resistor coupled between the second node and a ground potential; and a control chip for generating a driving signal in response to a voltage on the second node and a bandgap voltage during an activation phase of the LED driving apparatus, so as to switch the power switch and thus making the LED string to be operated under a constant current for producing light, and further comparing a detection voltage obtained in response to a voltage on the first node with a predetermined voltage, so as to stop generating the driving signal when the detection voltage is greater than the predetermined voltage.

Abstract: A light emitting diode (LED) driving apparatus is provided, which includes a power conversion circuit for receiving and converting an input power so as to generate a DC voltage to simultaneously drive a plurality of LED strings arranged in parallel; and a plurality of current regulation chips each having a single regulation channel and respectively corresponding to the LED strings, wherein an ith current regulation chip is only used for regulating a current flowing through an ith LED string, where i is a positive integer.

Abstract: A light-emitting-diode (LED) driving apparatus is provided, and which includes a power switch having a first terminal coupled to a first node and a second terminal coupled to a second node, wherein an LED string is coupled between a DC voltage and the first node; a first resistor coupled between the second node and a ground potential; and a control chip for generating a driving signal in response to a voltage on the second node and a bandgap voltage during an activation phase of the LED driving apparatus, so as to switch the power switch and thus making the LED string to be operated under a constant current for producing light, and further comparing a detection voltage obtained in response to a voltage on the first node with a predetermined voltage, so as to stop generating the driving signal when the detection voltage is greater than the predetermined voltage.

Abstract: A short circuit protection circuit applied to a driving circuit of light emitting diodes is coupled to a highest-voltage detection circuit, a current balance circuit, and a voltage-feedback control circuit for generating a driving-current control signal and a voltage-feedback control signal according to the highest voltage of the highest-voltage detection circuit to disable the current balance circuit and the voltage-feedback control circuit so as to implement short lamp protection.

Abstract: A light emitting diode (LED) driving apparatus is provided, which includes a power conversion circuit for receiving and converting an input power so as to generate a DC voltage to simultaneously drive a plurality of LED strings arranged in parallel; and a plurality of current regulation chips each having a single regulation channel and respectively corresponding to the LED strings, wherein an ith current regulation chip is only used for regulating a current flowing through an ith LED string, where i is a positive integer.

Abstract: A control circuit, applicable to a voltage regulator including a power switch. The control circuit includes a variable resistance generating unit and a detecting circuit. The variable resistance generating unit provides a variable resistor with resistance that varies over time. A reference current representing the current flowing through the power switch flows through the resistor to generate a first feedback voltage. The detecting circuit reduces the conduction of the power switch when the first feedback voltage is detected as being equal to or exceeding a predetermined voltage level.

Abstract: A control circuit, applicable to a voltage regulator including a power switch. The control circuit includes a variable resistance generating unit and a detecting circuit. The variable resistance generating unit provides a variable resistor with resistance that varies over time. A reference current representing the current flowing through the power switch flows through the resistor to generate a first feedback voltage. The detecting circuit reduces the conduction of the power switch when the first feedback voltage is detected as being equal to or exceeding a predetermined voltage level.

Abstract: A method to fabricate patterned strain-relaxed SiGe epitaxial with threading dislocation density control is provided. An ion-implanting area is first defined on a silicon substrate, and then proceeds ion-implanting. Finally, a buffer layer and a SiGe epitaxial layer are deposited. According to the disclosure, an active area and a non-active area are defined through ion-implanting. Therefore, the threading dislocation occurring in the active area concentrates in the non-active area, and the density of the threading dislocation is lowered. Furthermore, the performance of the semiconductor is also enhanced.

Abstract: A method to fabricate patterned strain-relaxed SiGe epitaxial with threading dislocation density control is provided. An ion-implanting area is first defined on a silicon substrate, and then proceeds ion-implanting. Finally, a buffer layer and a SiGe epitaxial layer are deposited. According to the disclosure, an active area and a non-active area are defined through ion-implanting. Therefore, the threading dislocation occurring in the active area concentrates in the non-active area, and the density of the threading dislocation is lowered. Furthermore, the performance of the semiconductor is also enhanced.

Abstract: A process of forming a low-strain crystal layer having low cell dislocation, low surface roughness and low thickness comprises: forming at least one crystal layer on a substrate; patterning the crystal layer by exposure and development to form an ion-doping region; doping ions in the ion-doping region of the crystal layer to convert the crystal layer to an amorphous layer; performing a planarization process on the amorphous layer; and annealing the amorphous layer to convert the amorphous layer to a low-strain crystal layer.

Abstract: A structure of the relaxed SiGe epitaxial layer and a fabrication method comprises a Si substrate, a Si interfacial layer positioning on the substrate, a SiGe graded buffer layer positioning on the Si interfacial layer, and a uniform SiGe epitaxy layer positioning on the SiGe graded buffer layer. It uses a mesa structure and obtains a highly relaxed SiGe epitaxial layer with a low defect density of threading dislocations, a smooth surface. A strained Si can be formed on the strained relaxation layer. The strained Si, the strained Ge, the strained Si/Ge can apply to the high-speed planar electronic devices. By using a mesa structure, it can efficiently decrease the required growth time and cost in the conventional relaxed SiGe epitaxy layer.