Patent application number | Description | Published |
20110157129 | SOURCE DRIVER CIRCUIT OF LIQUID CRYSTAL DISPLAY DEVICE - A source driver circuit of a liquid crystal display device including a gamma buffer. The gamma buffer includes a differential amplification section configured to differentially amplify an input signal; a current mirror section configured to operate as a current mirror; an enable section configured to convert the differential amplification section from a standby mode to an enable mode by a bias voltage; a power drop speed improvement section configured to respectively connect drains of the two PMOS transistors of the current mirror section and drains of the two NMOS transistors of the differential amplification section through two diode coupling type MOS transistors, and shorten a recovery time after a power drop; and an output section configured to be determined in a bias level thereof by the bias voltage and generate an output voltage according to a voltage of a downstream node on one side of the current mirror section. | 06-30-2011 |
20110164006 | DISPLAY DRIVE CIRCUIT - A display driving circuit includes a buffer section, an N-dot switch circuit, a charge sharing switch circuit, and a sharing voltage level control switch circuit. The buffer section buffers a plurality of pixel driving signals outputted from a plurality of DACs. The N-dot switch circuit selects paths of the plurality of pixel driving signals outputted from the buffer section in response to a first path selecting signal or a second path selecting signal that is determined depending upon a dot inversion method, and switches the paths to a plurality of output terminals. The charge sharing switch circuit shares charges among the plurality of output terminals in response to a charge sharing control signal. The sharing voltage level control switch circuit controls charge sharing between the plurality of output terminals and a voltage level upon charge sharing, in response to a sharing voltage level control signal. | 07-07-2011 |
20110169808 | AMPLIFIER INCLUDING DITHERING SWITCH AND DISPLAY DRIVING CIRCUIT USING THE AMPLIFIER - An amplifier and a display driving circuit. The amplifier includes an input stage, a bias stage and an output stage. The input stage determines voltage levels of two nodes in correspondence to two input voltages received in response to a first bias voltage, and includes four path selecting switches, two input transistors and one bias transistor. The bias stage generates two class AB output voltages which correspond to the voltage levels of the two nodes, and includes current mirrors, ten path selecting switches, class AB bias circuits and two bias transistors. The output stage generates an output voltage VOUT that corresponds to the two class AB output voltages, and includes two coupling capacitors and two push-pull transistors. The plurality of path selecting switches operate by one signal of a first path selecting signal and a second path selecting signal that are exclusively enabled with respect to each other. | 07-14-2011 |
20110199821 | POWER MANAGEMENT CHIP FURNISHED WITH VOLTAGE CONTROLLER - A power management IC includes a first IC having a boost converter IC which generates a second voltage using a first voltage supplied from an outside and supplies the second voltages to a charge pump, a reference voltage generation circuit, and an EEPROM; and a second IC configured to be inputted with a third voltage and a fourth voltage as outputs of the charge pump and output a fifth voltage and a sixth voltage. The second IC has a voltage regulator which regulates the third voltage and the fourth voltage or the fifth voltage and the sixth voltage and generates an eighth voltage and a ninth voltage as voltages required for programming operation or erasing operation of the EEPROM. | 08-18-2011 |
20110266962 | DRIVER IC FOR ELECTRICAL LOAD AND DRIVING METHOD THEREOF - A driver IC for electrical loads, suitable for regulating a driving voltage depending upon a feedback signal and supplying a regulated driving voltage to a power supply line to which load strings are connected in parallel. The driver IC includes driving current sources respectively connected to the load strings through regulated voltage nodes and configured to supply driving current to the load strings in response to a control signal; sensing units configured to sense and output a minimum voltage among voltages of the regulated voltage nodes; a sample-and-hold circuit configured to sample, hold and output the minimum voltage in response to the control signal; and a comparator configured to compare an output voltage of the sample-and-hold circuit and a reference threshold voltage and generate the feedback signal. | 11-03-2011 |
20110298769 | LIQUID CRYSTAL DISPLAY DRIVING CIRCUIT WITH LESS CURRENT CONSUMPTION - An LCD driving circuit includes a first buffer configured to have a terminal for a first voltage, a terminal for a second voltage and a terminal for an intermediate voltage between the first voltage and the second voltage, and be driven in a range from the first voltage to the intermediate voltage; and a second buffer configured to have a terminal for the first voltage, a terminal for the second voltage and a terminal for the intermediate voltage, and be driven in a range from the intermediate voltage to the second voltage. The terminal for the intermediate voltage of the first buffer and the terminal for the intermediate voltage of the second buffer are connected with each other, and the first voltage is a highest voltage, the second voltage is a lowest voltage, and the intermediate voltage is in a range from the first voltage to the second voltage. | 12-08-2011 |
20120169701 | READOUT INTEGRATED CIRCUIT FOR A TOUCH SCREEN - A readout integrated circuit (ROIC) for a touch screen, the readout integrated circuit includes: a touch sensor unit configured to include a plurality of touch sensors which are arranged in a matrix form having rows and columns in an inside or outside of a touch screen panel (TSP); a plurality of sensing blocks configured to sense an electrical change in each of the touch sensors, to convert the electrical change into a voltage value, and to store the voltage value; a delta circuit unit configured to receive a difference between two sensing voltage values stored in two sensing blocks, respectively, which are spaced by a predetermined distance and selected from among the plurality of sensing blocks, and to produce a delta (Ī) voltage; and an analog-to-digital converter configured to convert an analog signal output from the delta circuit unit into an N-bit digital signal (wherein, āNā is a natural number). | 07-05-2012 |
20130106296 | DEVICE FOR DRIVING LIGHT EMITTING DIODE | 05-02-2013 |
20130320868 | LED LIGHTING APPARATUS AND CONTROL CIRCUIT THEREOF - Disclosed is a light emitting diode lighting apparatus capable of improving a power factor and temperature characteristics. The light emitting diode lighting apparatus according to a preferred embodiment of the present invention includes a light source having a plurality of light emitting diode channels and performs a current regulating operation to allow a light source to emit light. The light source uses a current path provided by current regulating to emit light. | 12-05-2013 |
20140077715 | SYSTEM CONTROL UNIT, LED DRIVER INCLUDING THE SYSTEM CONTROL UNIT, AND METHOD OF CONTROLLING STATIC CURRENT OF THE LED DRIVER - Embodiments of the present invention provide a light-emitting diode (LED) driver for controlling a static current supplied to an LED array connected to a secondary coil of a transformer by using the peak values of currents flowing through a power transistor, which may reside in a switching element connected to a primary coil of the transformer. In some embodiments, the LED driver is configured to control the static current that flows through the LED array using an AC voltage supplied to the primary side of the transformer. In some embodiments, the LED driver includes a power conversion unit, a switching unit, a transformer, and a system control unit. In some embodiments, the method of controlling the static current of the LED driver includes a current peak value detection step, a step output current calculation step, a static current mean value calculation step, and a gate control signal update step. | 03-20-2014 |
20140111108 | SYSTEM CONTROL UNIT, LED DRIVER INCLUDING THE SYSTEM CONTROL UNIT, AND METHOD OF CONTROLLING STATIC CURRENT OF THE LED DRIVER - Embodiments of the present invention provide a light-emitting diode (LED) driver and method of controlling the static current of the LED driver. In some embodiments, the LED driver is configured to calculate output currents of a pulse form using a small number of parameters and adjust a gate control signal using the mean value of the output currents of a pulse form. Accordingly, the LED driver can be used to control a static current that flows through an LED array connected to a circuit on the secondary side of a transformer using a DC voltage or an AC voltage supplied to the primary side of the transformer. In some embodiments, the LED driver includes a power conversion unit, switching unit, transformer, zero current detection unit, and system control unit. In some embodiments, the system control unit is configured to adjust the gate control signal. | 04-24-2014 |
20150048744 | LIGHT EMITTING DIODE DRIVING CIRCUIT AND LIGHT EMITTING DIODE ILLUMINATION APPARATUS INCLUDING THE SAME - A LED driving circuit drives a plurality of LED (Light Emitting Diode) groups, has a common voltage that is changed according to an input voltage of the plurality of LED groups, and includes a common node, a plurality of phase switches arranged between the output terminals of the plurality of LED groups and the common node, and a plurality of phase switch control units that form current flows among a corresponding LED group, a corresponding phase switch, and the common node in phase sections of the input voltage based on the common voltage and a corresponding reference voltage, the input voltage having a time-variable phase. Accordingly, the LED driving circuit can correct a power factor without using an inductor or a capacitor. | 02-19-2015 |