Abstract: An average current controller configured for connection to display-components through a power switch. The average current controller includes first, second, and third comparators, an integrator, and a reference current generator. The first comparator compares a peak current level of reference current with a load current level of load current and outputs a first comparison result. The load current denotes current flowing through the display-components. The second comparator compares the peak current level of reference current with an average current level of the load current and outputs a second comparison result. The integrator integrates the second comparison result. The third comparator compares the integral value of the integrator with a predetermined value and outputs a third comparison result. The reference current generator sets the peak current level based on the first comparison result and the third comparison result and generates the reference current with the set peak current level.

Abstract: There is provided an apparatus for driving a light emitting diode (LED), capable of distributing current stress applied to the LED. The apparatus includes an LED part including a plurality of LED units respectively including at least one LED, the plurality of LED units being connected in parallel to a power input terminal to which rectified power in sine wave form is supplied, and, among the plurality of LED units connected in parallel, a termination end of the LED unit in a front end being connected to a middle of an adjacent LED unit; and a current source unit including a plurality of current sources respectively connected to termination ends of the plurality of LED units and allowing corresponding current to flow through the plurality of LED units.

Abstract: An isolated flyback converter for an LED driver includes a snubber circuit unit connected to the primary side of a transformer; and a snubber voltage detection unit which detects a snubber voltage of the snubber circuit unit and generates a reference voltage proportional to the detected snubber voltage. Further, the isolated flyback converter includes a switching unit with a source terminal and a drain terminal, and may be turned on or off in response to an arbitrary logic signal. Furthermore, the isolated flyback converter includes a control unit which compares a voltage supplied through the switching current sensing resistor with the reference voltage, and supplies a logic signal at relatively high level or relatively low level to the switching unit to control the switching unit such that a secondary-side current of the transformer is maintained relatively constant.

Abstract: There is provided a light emitting diode driving apparatus capable of supplying a constant average current to a light emitting diode by generating a reference voltage used for driving the light emitting diode according to input power and a switching signal switching a path of a current supplied to the light emitting diode. The light emitting diode driving apparatus includes: a reference voltage generating unit generating a reference voltage set based on input power and a switching signal for supplying driving power to a light emitting diode; and a driving unit supplying the driving power to the light emitting diode according to the reference voltage.

Abstract: A driver circuit is configured to drive light-emitting elements. The driver circuit includes a light-emitting element, a power switching element, a control circuit, and a charge pump circuit. The power switching element includes a first terminal connected to the light-emitting element and turns on and off the light-emitting element. The control circuit is connected to a second terminal of the power switching element and controls a switching operation of the power switching element. The charge pump circuit is connected between the control circuit and a power source for the light-emitting element and supplies current to the control circuit for driving the control circuit.

Abstract: An isolated flyback converter for an LED driver may include: (1) A snubber circuit configured to be connected to the primary side of a transformer. (2) A switching unit configured to have a source terminal and a drain terminal and configured to be turned on or off. (3) A control unit configured to detect a first input signal proportional to a fluctuation in the power supply voltage, detect a second input signal when the switching unit is turned off, generate a signal inversely proportional to the maximum value of the first input signal and multiply the generated signal to the second input signal, and control a peak current of the switching unit to be proportional to the multiplication result of the signal inversely proportional to the maximum value of the first input signal and the second input signal such that a secondary-side current of the transformer is maintained constant.

Abstract: An isolated flyback converter for an LED driver includes a snubber circuit unit connected to the primary side of a transformer; and a snubber voltage detection unit which detects a snubber voltage of the snubber circuit unit and generates a reference voltage proportional to the detected snubber voltage. Further, the isolated flyback converter includes a switching unit with a source terminal and a drain terminal, and may be turned on or off in response to an arbitrary logic signal. Furthermore, the isolated flyback converter includes a control unit which compares a voltage supplied through the switching current sensing resistor with the reference voltage, and supplies a logic signal at relatively high level or relatively low level to the switching unit to control the switching unit such that a secondary-side current of the transformer is maintained relatively constant.

Abstract: The present invention relates to a power factor correction circuit and a method of driving the power factor correction circuit. The power factor correction circuit according to the present invention includes a power transfer element configured to receive an input voltage, an input current corresponding to the input voltage flowing through the power transfer element, and a switch connected to the power transfer element and configured to control an output voltage generated by the current flowing through the power transfer element.

Abstract: An average current controller configured for connection to display-components through a power switch. The average current controller includes first, second, and third comparators, an integrator, and a reference current generator. The first comparator compares a peak current level of reference current with a load current level of load current and outputs a first comparison result. The load current denotes current flowing through the display-components. The second comparator compares the peak current level of reference current with an average current level of the load current and outputs a second comparison result. The integrator integrates the second comparison result. The third comparator compares the integral value of the integrator with a predetermined value and outputs a third comparison result. The reference current generator sets the peak current level based on the first comparison result and the third comparison result and generates the reference current with the set peak current level.

Abstract: An apparatus configured to generate control data. The apparatus includes a counter unit configured to receive an input signal having a first state and a second state and counts the first state in the input signal, a delay unit configured to delay the count value for a predetermined time, and a data output unit configured to receive the delayed count value from the counter unit and then generate the control data based on the delayed count value.

Abstract: A driver circuit is configured to drive light-emitting elements. The driver circuit includes a light-emitting element, a power switching element, a control circuit, and a charge pump circuit. The power switching element includes a first terminal connected to the light-emitting element and turns on and off the light-emitting element. The control circuit is connected to a second terminal of the power switching element and controls a switching operation of the power switching element. The charge pump circuit is connected between the control circuit and a power source for the light-emitting element and supplies current to the control circuit for driving the control circuit.

Abstract: Disclosed are a switch controller, a switch control method, and a converter based thereon. The switch controller generates an input sensing voltage corresponding to the input voltage of the converter, and compares the input sensing voltage with a predetermined first reference value. The switch controller generates a zero cross detection signal with a first level or a second level depending upon the comparison result, and generates a reference clock signal varying in frequency in accordance with one cycle of the zero cross detection signal. The switch controller generates digital signals by using the reference clock signal and the zero cross detection signal. The digital signals synchronize with the zero cross detection signal, and increase in accordance with the reference clock signal during a half of one cycle of the zero cross detection signal, while decreasing in accordance with the reference clock signal during the other half cycle of the zero cross detection signal.

Abstract: In one embodiment, a power integrated circuit device is provided. The power integrated circuit device includes a high-side power switch having a high voltage transistor and a low voltage transistor. The high voltage transistor has a gate, a source, and a drain, and is capable of withstanding a high voltage applied to its drain. The low voltage transistor has a gate, a source, and a drain, wherein the drain of the low voltage transistor is connected to the source of the high voltage transistor and the source of the low voltage transistor is connected to the gate of the high voltage transistor, and wherein a control signal is applied to the gate of the low voltage transistor from the power integrated circuit device.

Abstract: The present invention relates to a power factor correction circuit and a method of driving the power factor correction circuit. The power factor correction circuit according to the present invention includes a power transfer element configured to receive an input voltage, an input current corresponding to the input voltage flowing through the power transfer element, and a switch connected to the power transfer element and configured to control an output voltage generated by the current flowing through the power transfer element.

Abstract: Disclosed are a switch controller, a switch control method, and a converter based thereon. The switch controller generates an input sensing voltage corresponding to the input voltage of the converter, and compares the input sensing voltage with a predetermined first reference value. The switch controller generates a zero cross detection signal with a first level or a second level depending upon the comparison result, and generates a reference clock signal varying in frequency in accordance with one cycle of the zero cross detection signal. The switch controller generates digital signals by using the reference clock signal and the zero cross detection signal. The digital signals synchronize with the zero cross detection signal, and increase in accordance with the reference clock signal during a half of one cycle of the zero cross detection signal, while decreasing in accordance with the reference clock signal during the other half cycle of the zero cross detection signal.

Abstract: In one embodiment, a power switch driving circuit is provided for a fluorescent lamp ballast. The circuit includes a first power switch driven by a first driver. A controller has a first output terminal for outputting a control signal for controlling the first driver. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal.

Abstract: A resonant inverter includes a first driver and a second driver for driving a first and second switching devices, respectively, a dead time generator for generating a first drive signal and a second drive signal respectively, a current-controlled oscillator for supplying, to the dead time generator, an output clock having a frequency determined based on a first current input to the current-controlled oscillator, and a current mirror for supplying the first current to the current-controlled oscillator in an amount proportional to a second current flowing through an external resistor. The current mirror includes a track/hold circuit, to supply the second current in an amount equal to an amount of the second current supplied before a variation in the amount of the second current, during a transition of an output signal between the first and second switching devices.

Abstract: A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.

Abstract: In one embodiment, a power switch driving circuit is provided for a fluorescent lamp ballast. The circuit includes a first power switch driven by a first driver. A controller has a first output terminal for outputting a control signal for controlling the first driver. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal.

Abstract: A high voltage gate driver circuit according to an embodiment of the present invention controls an operational range of an output signal of a level shifter to be appropriate for an operational range of a reshaper through a VIV converter. Even though the voltage range of the signal which is input from the high voltage gate driver circuit to the level shifter is different from the operational range of the reshaper, the input signal can always be recognized exactly regardless of the VTH voltage of the reshaper by controlling the operational range of the signal through the VIV converter. In addition, incorrect operation of the circuit can be prevented by erasing a common mode noise which is input with the input signal.