Abstract: Provided are a ramp circuit and a DC-DC converter. The ramp circuit generates a current flowing in a resistor using voltages affected by an output voltage and an input voltage of a DC-DC converter, and generates a ramp signal through copying of the current and charging and discharging of a capacitor using a current mirror unit. The ramp signal is generated by considering the input voltage and the output voltage, and thus the ramp signal has an optimal slope to provide an adaptive response to state change in the input voltage and the output voltage. The DC-DC converter uses such a ramp circuit to facilitate its operation.

Abstract: A Light Emitting Diode (LED) driver apparatus is provided. The LED driver apparatus includes: a Pulse Width Modulation (PWM) signal generator configured to generate a PWM signal, a DC-DC converter configured to provide a driving voltage of a plurality of LED arrays by using the generated PWM signal, and a sensor configured to determine whether at least one LED array among the plurality of LED arrays is in an open state in response to the driving voltage being higher than or equal to a preset first reference voltage, and the preset first reference voltage is higher than the driving voltage applied when the plurality of LED arrays are each in a working state.

Abstract: A discharge circuit of a device including a drive circuit operating by an inputted negative voltage includes: a discharge unit connected between a first input terminal receiving the negative voltage and a second input terminal receiving a ground voltage, and configured to discharge the negative voltage to the ground voltage of the second input terminal in response to a control signal; and a control unit connected between the first input terminal and a third input terminal receiving an operation voltage corresponding to a normal operation mode and an abnormal operation mode of the drive circuit, and configured to generate the control signal in response to an operation signal for determining an operation state and a non-operation state in the normal operation mode of the drive circuit.

Abstract: A light emitting diode (LED) driver apparatus includes a pulse-width modulation (PWM) signal generator configured to generate a PWM signal according to a reference voltage. The LED driver apparatus also includes a DC-DC converter configured to provide a driving voltage to LED arrays based on the generated PWM signal, and a LED driver configured to drive the LED arrays through output ports. The LED apparatus includes a detector configured to detect whether the LED arrays are operatively connected to the corresponding output ports.

Abstract: A detection circuit configured to detect a short in a plurality of LED arrays is provided. The detection circuit includes a voltage measuring unit, a short detecting unit, and a detection control unit. The voltage measuring unit is configured to measure respective feedback voltages of the plurality of LED arrays and output a lowest measured feedback voltage as a first feedback voltage. The short detecting unit is configured to detect the short in the LED arrays using the measured feedback voltages. The detection control unit is configured to control the short detecting unit to stop short detection operation, when the first feedback voltage exceeds a first preset reference voltage.

Abstract: A detecting circuit and method thereof are configured to detect whether an LED array is open is described. The detecting circuit includes a resistance unit, a first switching unit, and an output unit. The resistance unit is operatively connected in series to the LED array. The switching unit is configured to be turned on when a voltage of the resistance unit is greater than or equal to a predetermined voltage level. The output unit is configured to produce an output indicative of whether the LED array is open, based whether the first switching unit is turned on.

Abstract: A light-emitting diode (LED) driver apparatus is provided. The LED driver apparatus includes a pulse width modulation (PWM) signal generating unit, a DC-DC converter, and a comparison voltage generating unit. The PWM signal generating unit generates a PWM signal according to a comparison voltage. The DC-DC converter supplies a driving voltage of an LED array by using the PWM signal. The comparison voltage generating unit measures a feedback voltage of the LED array and supplies a difference between the measured feedback voltage and a target voltage as a comparison voltage to the PWM signal generating unit. The comparison voltage generating unit supplies a second reference voltage as a comparison voltage to the PWM signal generating unit from a time when the driving voltage is higher than or equal to a first reference voltage to a time when the driving voltage reaches the target voltage.

Abstract: A Light Emitting Diode (LED) driving apparatus and a method of driving a LED backlight unit are provided. An LED driving apparatus includes: an input unit configured to receive a dimming signal, an extension unit configured to extend ON time of the inputted dimming signal, an LED driving unit configured to drive an LED array using the extended dimming signal, and a detection unit configured to detect a degradation of the LED array by measuring a forward voltage between the LED array and the LED driving unit.

Abstract: A Light Emitting Diode (LED) driver apparatus is provided. The LED driver apparatus includes: a Pulse Width Modulation (PWM) signal generator configured to generate a PWM signal, a DC-DC converter configured to provide a driving voltage of a plurality of LED arrays by using the generated PWM signal, and a sensor configured to determine whether at least one LED array among the plurality of LED arrays is in an open state in response to the driving voltage being higher than or equal to a preset first reference voltage, and the preset first reference voltage is higher than the driving voltage applied when the plurality of LED arrays are each in a working state.

Abstract: A Light Emitting Diode (LED) driver apparatus and a method of driving an LED array are provided. A Light Emitting Diode (LED) driver apparatus includes: a DC-DC converter configured to supply a driving voltage to an LED array, a plurality of LED drivers configured to drive the LED array according to a dimming signal, in which the plurality of LED drivers are connected to one another in parallel to supply currents to the LED array.

Abstract: A LED driving circuit having a sensing unit is disclosed. The LED driving circuit includes an input unit configured to receive a dimming signal to drive an LED array, a DC-DC converter including a power transistor configured to perform a switching operation, the DC-DC converter being configured to provide an output voltage to the LED array by the switching operation, a PWM signal generating unit configured to provide a PWM signal to adjust power of the LED array to the power transistor, a LED driving unit configured to drive the LED array using the dimming signal, and a sensing unit configured to sense degradation of the power transistor.

Abstract: A Light Emitting Diode (LED) driver circuit and a Pulse Width Modulation (PWM) controlling circuit thereof is provided. The LED driver circuit includes a voltage detector connected to a plurality of LED arrays, the voltage detector being configured to determine a connection status of each of the LED arrays according to a level of a feedback voltage of each of the LED arrays, and detect a minimum feedback voltage from the feedback voltage of each of the LED arrays that are determined to be connected, a controller configured to output a control signal to control boosting of the LED arrays according to the detected minimum feedback voltage, a PWM signal generator configured to output a PWM signal corresponding to the outputted control signal, and a driving voltage generator configured to supply a driving voltage commonly to the LED arrays according to the PWM signal.

Abstract: A plasma display according to an exemplary embodiment of the present invention applies different driving methods according to a maximum grayscale level of image data input for one field. When the maximum grayscale level of the field is higher than a reference level, an address period for selecting a light emitting cell and a non-light emitting cell from a plurality of discharge cells and a sustain period for sustain-discharging light emitting cells among the plurality of discharge cells are simultaneously driven in a plurality of sequential subfields after a first subfield. When the maximum grayscale level of the field is less than the reference level, the address period and the sustain period are time-separately driven in the plurality of subfields.

Abstract: A display driving circuit is provided. The display driving circuit includes first to third voltage generation units configured to receive an externally applied input voltage having a same magnitude and generate respective voltages having different magnitudes, and a latch-up prevention unit connected to the second voltage generation unit and configured to receive a lower voltage among voltages output from the second voltage generation unit and to ground the lower voltage for a preset period of time.

Abstract: A plasma display device includes a plasma display panel for displaying an image by a gas discharge. A chassis base is attached to the plasma display panel and supports the plasma display panel. At least one printed circuit board is mounted on the a side of the chassis base at opposite the side supporting the plasma display panel. At least one flexible printed circuit connects electrodes of the plasma display panel and terminals of the printed circuit boards. An anisotropic conductive film is between the terminal of the printed circuit board and a terminal of the flexible printed circuit and connects the terminal of the printed circuit board and the terminal of the flexible printed circuit. The printed circuit board includes at least one dummy groove outside a region of the printed circuit board facing the flexible printed circuit.

Abstract: A ESD protection circuit includes: a first clamp connected between a first power line and a ground line; a second clamp connected between the ground line and a second power line; a first output buffer connected between the first power line and the ground line, and providing a first operating voltage; a second output buffer connected between the ground line and the second power line, and providing a second operating voltage; a first switch unit configured to transfer the first operating voltage to an I/O pad; a second switch unit configured to transfer the second operating voltage to the I/O pad; a first transfer unit comprising one or more diodes connected in series between the first power line and the I/O pad; and a second transfer unit comprising one or more diodes connected in series between the I/O pad and the second power line.

Abstract: When a current frame of a video expresses only grayscales less than a reference grayscale, a sustain pulse applying period and a holding period are alternately provided in a sustain period of at least one subfield having a weight greater than a reference weight in all of the discharge cells of a plasma display panel, thereby reducing power consumption in the plasma display panel. In the sustain pulse applying period, sustain pulses alternately having a first voltage and a second voltage less than the first voltage are applied in opposite phases to first electrodes and second electrodes of the plasma display panel. In the holding period, the first electrodes and/or the second electrodes are maintained at the first voltage.

Abstract: In an apparatus and method for sharing schedule information between mobile terminals, a sending mobile terminal transmits schedule information input by a user to a receiving mobile terminal. A schedule management server monitors a position of the sending mobile terminal according to the schedule information. If the current position of the sending mobile terminal is different from position information included in the schedule information, schedule change information is transmitted to the receiving mobile terminal, which outputs the schedule information.

Abstract: A plasma display device with improved heat dissipation performance of a driver integrated circuit is disclosed. In one embodiment, the plasma display device includes i) plasma display panel configured to display an image, iii) a printed circuit board assembly, iii) a flexible printed circuit configured to electrically connect the printed circuit board assembly to the plasma display panel, wherein the flexible printed circuit comprises a metal layer and iv) a driver integrated circuit mounted in the flexible printed circuit and configured to control an electrode formed in the plasma display panel. The driver integrated circuit comprises: i) a base, ii) a plurality of output terminals connected to the base, and iii) a heat-conducting layer contacting 1) at least one of the plurality of output terminals and 2) the metal layer of the flexible printed circuit, wherein the heat-conducting layer and the metal layer are at least partially embedded in the flexible printed circuit.

Abstract: A display device is provided having enhanced precision and accuracy in attachment of a plasma display panel to a chassis base. A method and apparatus for manufacturing such a display device is also provided. The display device may include a display panel having an upper panel and a lower panel and a chassis base for supporting the display panel. At least one panel of upper and lower panels in a plasma display panel is marked with an aligning mark, and a penetration hole is formed at a chassis base at a position corresponding to the aligning mark. Therefore, the chassis base and the plasma display panel may be precisely aligned on the basis of the aligning mark exposed through the penetration hole.