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: An LED driving circuit is provided. The LED driving circuit includes an input unit which receives an input dimming signal for driving an LED array, a PWM signal generating unit which extends an on-period of the input dimming signal to form an extended dimming signal, and generates a PWM signal using the extended dimming signal, a DC-DC converter which supplies output voltage to the LED array using the PWM signal, and an LED driving unit which drives the LED array using the input dimming signal.

Abstract: A PWM signal generating circuit and method, and an LED driver circuit using same, is disclosed. The PWM signal generating circuit generates a PWM signal for a DC-DC converter using a dimming signal, and includes an oscillator which generates a first clock signal having a predetermined frequency, a synchronizing unit which synchronizes the dimming signal to the first clock signal, and a PWM signal generating unit which generates the PWM signal in response to the first clock signal having a falling edge while the synchronized dimming signal is on.

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 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 Pulse Width Modulation (PWM) controlling circuit and a Light Emitting Diode (LED) driver circuit having the same are provided. An 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 corresponding level of the feedback voltage, and detect a minimum feedback voltage from feedback voltages of the LED arrays that are determined to be connected, a controller configured to output a control signal to one of abort and control boosting of the LED arrays according to the detected minimum feedback voltage, and a Pulse Width Modulation (PWM) signal generator configured to output a PWM signal corresponding to the outputted control signal according to an on/off state of a dimming signal that drives the LED arrays that are determined to be connected.

Abstract: A level shifter is provided. The level shifter includes a signal converter connected to an external power source and a ground, first and second output terminals connected to the signal converter, the first and second output terminals being configured to output a bias voltage applied from the external power source, and a switching unit configured to switch a connection state of the signal converter according to an input signal to adjust output voltage values of the first and second output terminals, the switching unit including first and second transistors, the first transistor being of a type that is different from a type of the second transistor, the first and second transistors being connected to each other in series between an input terminal, to which an input signal is applied, and the external power source, gates of the first and second transistors being commonly connected to the second output terminal.

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 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 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 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 Pulse Width Modulation (PWM) controlling circuit and a Light Emitting Diode (LED) driver circuit having the same are provided. An 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 corresponding level of the feedback voltage, and detect a minimum feedback voltage from feedback voltages of the LED arrays that are determined to be connected, a controller configured to output a control signal to one of abort and control boosting of the LED arrays according to the detected minimum feedback voltage, and a Pulse Width Modulation (PWM) signal generator configured to output a PWM signal corresponding to the outputted control signal according to an on/off state of a dimming signal that drives the LED arrays that are determined to be connected.

Abstract: A level shifter is provided. The level shifter includes a signal converter connected to an external power source and a ground, first and second output terminals connected to the signal converter, the first and second output terminals being configured to output a bias voltage applied from the external power source, and a switching unit configured to switch a connection state of the signal converter according to an input signal to adjust output voltage values of the first and second output terminals, the switching unit including first and second transistors, the first transistor being of a type that is different from a type of the second transistor, the first and second transistors being connected to each other in series between an input terminal, to which an input signal is applied, and the external power source, gates of the first and second transistors being commonly connected to the second output terminal.

Abstract: A PWM signal generating circuit and method, and an LED driver circuit using same, is disclosed. The PWM signal generating circuit generates a PWM signal for a DC-DC converter using a dimming signal, and includes an oscillator which generates a first clock signal having a predetermined frequency, a synchronizing unit which synchronizes the dimming signal to the first clock signal, and a PWM signal generating unit which generates the PWM signal in response to the first clock signal having a falling edge while the synchronized dimming signal is on.

Abstract: An LED driving circuit is provided. The LED driving circuit includes an input unit which receives an input dimming signal for driving an LED array, a PWM signal generating unit which extends an on-period of the input dimming signal to form an extended dimming signal, and generates a PWM signal using the extended dimming signal, a DC-DC converter which supplies output voltage to the LED array using the PWM signal, and an LED driving unit which drives the LED array using the input dimming signal.

Abstract: The present invention provides a time division controlled (TDC) panel driver for reducing flickers. The TDC panel driver includes an address counter for counting a pixel address of a line corresponding to a predetermined resolution of a TDC panel to thereby output a counting value; a timing generating block for comparing the counting value and a predetermined order value to thereby output a read start signal; a timing controller for generating a line address in response to the read start signal and outputting a memory read control signal; and a memory for performing a memory read and a memory write operations, wherein a start timing for the memory read operation of the memory is controlled by the memory read control signal.