Abstract: A proportional to absolute temperature (PTAT) current generation circuit may include a current mirror unit and/or a level control unit. The current mirror unit may be connected between a first power supply voltage, a first node, and/or a second node. The level control unit may be connected between the first node, the second node, and/or a second power supply voltage. The level control unit may be configured to control a level of an output current of the current mirror unit based on a voltage level of the first node and a voltage level of the second node. The level control unit may include a first transistor connected between the first node and the second power supply voltage, at least one second transistor connected between the second node and a third node, the at least one second transistor configured to operate in a weak inversion region, and/or a third transistor connected between the third node and the second power supply voltage.

Abstract: A display driver integrated circuit (IC) includes a grayscale voltage generator, a main decoder unit, a pre-decoder unit, and an output buffer unit. The grayscale voltage generator is configured to receive at least one gamma reference voltage and generate a plurality of grayscale voltages. The main decoder unit is configured to receive the grayscale voltages and data, decode the data, and selectively output a grayscale voltage based on the decoded result. The pre-decoder unit is configured to decode part of the data and output a precharge voltage. The output buffer unit is configured to sequentially receive an output of the pre-decoder unit and an output of the main-decoder unit, and output grayscale data used for driving a display device.

Abstract: A digital to analog converter includes a first decoder, a gamma reference voltage decoder unit and an active resistor string unit. The first decoder receives 2(N-2) first gamma voltages and selects 2(N-2-P) second gamma voltages among the first gamma voltages in response to P bit data, where N is an odd number not less than 9, and N?1=2P. The gamma reference voltage decoder unit selects successive two high gamma tab voltages among N high gamma tab voltages in response to the P bit data and provides the selected successive two high gamma tab voltages as a first gamma reference voltage and a second gamma reference voltage. The active resistor string unit divides the first gamma reference voltage and the second gamma reference voltage and provides 2(N-2) grayscale voltages.

Abstract: A source driving circuit includes a shift register, a data latch circuit, a D/A converter, and a sample-and-hold circuit. The shift register generates an n-bit first signal in response to a clock signal and an input/output control signal, wherein n is a positive integer. The data latch circuit samples video data using the first signal to latch the sampled video data, and outputs 3×n digital signals. The D/A converter generates a plurality of analog voltage signals corresponding to the 3×n digital signals using a plurality of gray scale voltages. The sample-and-hold circuit generates 6×n sample-and-hold signals using the analog voltage signals in response to a plurality of switching control signals.

Abstract: A proportional to absolute temperature (PTAT) current generation circuit may include a current mirror unit and/or a level control unit. The current mirror unit may be connected between a first power supply voltage, a first node, and/or a second node. The level control unit may be connected between the first node, the second node, and/or a second power supply voltage. The level control unit may be configured to control a level of an output current of the current mirror unit based on a voltage level of the first node and a voltage level of the second node. The level control unit may include a first transistor connected between the first node and the second power supply voltage, at least one second transistor connected between the second node and a third node, the at least one second transistor configured to operate in a weak inversion region, and/or a third transistor connected between the third node and the second power supply voltage.

Abstract: A source driver circuit provides a source driving signal to a disconnected source line. The source driver circuit includes a shift register, a latch unit, a DAC unit, a buffer unit, and a source line repair circuit. A source line repair circuit receives a common voltage signal and a source driving signal corresponding to the disconnected source line, selects an amplifier having a same polarity type as a polarity type of an amplifier constituting the buffer unit in response to a source driving signal to provide an output signal of the selected amplifier to the disconnected source line. The source driver circuit includes the source line repair circuit which may select the amplifier having the same polarity as the polarity of the amplifier of the buffer, and thus may safely provide the source driving signal to the disconnected source line.

Abstract: A method and apparatus is described that may be capable of improving picture quality of a TFT-LCD device, to prevent occurrence of a stripe phenomenon caused by an offset, i.e., differences among the voltages output from a plurality of amplifiers in a TFT-LCD source driver circuit. The method and apparatus may eliminate differences among voltages output from a plurality of amplifiers in a circuit such as a TFT-LCD source driver circuit. In the method, a panel driving voltage may be applied to a given pixel of a liquid crystal panel in response to a clock signal. The polarity of the applied panel driving voltage may be changed in response to a polarity control signal, and a switch control signal may be generated based on the polarity control signal. The switch control signal may be applied to switch first and second input ports of each of the plurality of amplifiers.

Abstract: An output buffer with an improved slew rate and method thereof. The output buffer may include a differential amplifier, a controller and an output unit. The output buffer may generate a pull signal and a control signal based on received input and output signals. The controller may transition an output node to a control voltage in response to the control signal and a bias voltage. The output unit may maintain the first output signal between a given voltage and the control voltage based on the pull signal and the bias voltage.

Abstract: An output buffer with an improved slew rate and method thereof. The output buffer may include a differential amplifier, a controller and an output unit. The output buffer may generate a pull signal and a control signal based on received input and output signals. The controller may transition an output node to a control voltage in response to the control signal and a bias voltage. The output unit may maintain the first output signal between a given voltage and the control voltage based on the pull signal and the bias voltage.

Abstract: A source driving circuit includes a shift register, a data latch circuit, a D/A converter, and a sample-and-hold circuit. The shift register generates an n-bit first signal in response to a clock signal and an input/output control signal, wherein n is a positive integer. The data latch circuit samples video data using the first signal to latch the sampled video data, and outputs 3×n digital signals. The D/A converter generates a plurality of analog voltage signals corresponding to the 3×n digital signals using a plurality of gray scale voltages. The sample-and-hold circuit generates 6×n sample-and-hold signals using the analog voltage signals in response to a plurality of switching control signals.

Abstract: A source driver circuit provides a source driving signal to a disconnected source line. The source driver circuit includes a shift register, a latch unit, a DAC unit, a buffer unit, and a source line repair circuit. A source line repair circuit receives a common voltage signal and a source driving signal corresponding to the disconnected source line, selects an amplifier having a same polarity type as a polarity type of an amplifier constituting the buffer unit in response to a source driving signal to provide an output signal of the selected amplifier to the disconnected source line. The source driver circuit includes the source line repair circuit which may select the amplifier having the same polarity as the polarity of the amplifier of the buffer, and thus may safely provide the source driving signal to the disconnected source line.

Abstract: A method and apparatus is described that may be capable of improving picture quality of a TFT-LCD device, to prevent occurrence of a stripe phenomenon caused by an offset, i.e., differences among the voltages output from a plurality of amplifiers in a TFT-LCD source driver circuit. The method and apparatus may eliminate differences among voltages output from a plurality of amplifiers in a circuit such as a TFT-LCD source driver circuit. In the method, a panel driving voltage may be applied to a given pixel of a liquid crystal panel in response to a clock signal. The polarity of the applied panel driving voltage may be changed in response to a polarity control signal, and a switch control signal may be generated based on the polarity control signal. The switch control signal may be applied to switch first and second input ports of each of the plurality of amplifiers.