Himax Technologies, Inc.

Ncku Research and Development Foundation

Jia-Hui Wang

Chien-Hung Tsai

Hung-Yu Huang

Chuan-Chien Hsu

Ying-Lieh Chen

Chin-Tien Chang

Chen-Yu Wang

Jing-Chuan Qiu

Ching-Chung Lee

Yi-Lun Chiang

An amplifier with enhanced slew rate includes an input stage including a first channel coupled to receive differential inputs and a second channel coupled to receive the differential inputs; a middle stage including a first current source coupled to receive outputs of the second channel and electrically connected to power, a second current source coupled to receive outputs of the first channel and electrically connected to ground, and a floating current source electrically connected between the first current source and the second current source; and an output stage coupled to the middle stage to generate an output voltage. A transit circuit is disposed in the input stage or the middle stage, controlled by the output stage, and configured to supply extra current during signal transition of the differential inputs, thereby enhancing the slew rate.

Amplifier with enhanced slew rate

An output amplifier of a source driver and a control method thereof are provided. The output amplifier includes a first switch circuit, a second switch circuit, a third switch circuit, a first input stage circuit, a second input stage circuit, a first active load circuit, a second active load circuit, a first positive output stage circuit, a first negative output stage circuit, a second positive output stage circuit and a second negative output stage circuit. In a first display stage of the control method, the first switch circuit outputs a positive reference signal through a first output terminal and outputs a negative reference signal through a second output terminal. In a second display stage of the control method, the signals outputted by the first output terminal and the second output terminal are exchanged.

Output amplifier of a source driver and control method thereof

A driving apparatus and a method for driving a display panel thereof are provided. The driving apparatus includes an output buffer, a switch, an adjusting circuit, a digital-to-analog converter and a code detecting unit. The output buffer provides an output voltage to a load according to a static current determining a speed of the output voltage reaching a target voltage for driving the load. The switch is coupled between the output buffer and the load in series, and is turned on or off according to a control signal. The code detecting unit detects an input code. The adjusting circuit determines whether the input code varies when the control signal is enabled, and disables a high driving ratio signal when the input code does not vary when the control signal is enabled. An enabling period of the high driving ratio signal is different from an enabling period of the control signal.

Driving apparatus and method for driving display panel thereof

A voltage sensing circuit is provided. The voltage sensing circuit includes two differential amplifiers and a buffer. The first differential amplifier receives a first input voltage and a first reference voltage and provides a first current and a second current according to the difference between the first input voltage and the first reference voltage. The second differential amplifier receives a second input voltage and a second reference voltage and provides a third current and a fourth current according to the difference between the second input voltage and the second reference voltage. The buffer is coupled to the two differential amplifiers. The buffer generates an output voltage based on the first current, the second current, the third current, and the fourth current.

Voltage sensing circuit

An amplifier, a dynamic-bias generation device of the amplifier and a dynamic-bias method of the amplifier are provided. The dynamic-bias generation device comprises an input stage, an output stage, a detection unit, a dynamic-bias generation unit and a switch unit. The input stage having a plurality of bias terminals converts an input signal of the amplifier into at least one current signal according to the voltage of the bias terminals. The output stage receives and converts the current signal into an output signal of the amplifier. The detection unit detects the current signal. The dynamic-bias generation unit generates a plurality of bias voltages according to the current signal. The switch unit dynamically determines the connection relations between the bias voltages of the dynamic-bias generation unit and the bias terminals of the input stage according to the detection result of the detection unit.

Amplifier and dynamic-bias generation device and dynamic-bias method thereof

A source driver adapted to drive a display panel is provided herein. The source driver includes a first output buffer, a detection module and a conversion module. The first output buffer enhances a first pixel signal and thereby outputs a first enhanced pixel signal. The detection module detects a rise time of the first enhanced pixel signal. The conversion module adjusts a driving capability of the first output buffer in response to the rise time for adjusting a slew rate of the first output buffer. Therefore, the first output buffer in the source driver can dynamically and automatically adjusts the slew rate of the first output buffer through a feedback mechanism composed of the detection module and the conversion module.

Source driver

A digital-to-analog conversion apparatus and a current-mode interpolation buffer thereof are provided. The current-mode interpolation buffer comprises a current source, a first differential transistor pair, a second differential transistor pair and an output stage. The current source outputs a first current and draws a second current. Wherein, the amperages of the first current and the second current are dependent on a digital code. First differential transistor pair generates a first differential current according a first rough voltage, an analog voltage and the first current. Second differential transistor pair generates a second differential current according a second rough voltage, the analog voltage and the second current. Output stage generates the analog voltage according to the first differential current and the second differential current, where the analog voltage belongs to a rough range from the first rough voltage to the second rough voltage.

Digital-to-analog conversion apparatus and current-mode interpolation buffer thereof

A buffering circuit with reduced power consumption is provided. The output buffering circuit includes first and second amplifier circuits. The first amplifier circuit includes a first input stage and a first output stage both coupled between a first power voltage and a second power voltage lower than the first power voltage, and an assistant discharging unit configured to provide a discharging current flowing from a first output node to a first intermediate power voltage during a discharging operation of the first amplifier circuit. The second amplifier circuit includes a second input stage and a second output stage both coupled between the first power voltage and the second power voltage, and an assistant charging unit configured to provide a charging current flowing from a second intermediate power voltage to a second output node during a charging operation of the second amplifier circuit. The first and second amplifier circuits can have reduced output voltage ranges and hence reduced total power consumption.

Buffering circuit with reduced dynamic power consumption

An output buffer and a source driver for a display panel are provided. The output buffer includes a differential input stage, a bias current source, a feedback module, and an output stage. The differential input stage has a first input terminal and a second input terminal receiving a first input signal and a second input signal respectively, and a first output terminal. The bias module provides a bias current to the differential input stage. The output stage has a second output terminal coupled to the first input terminal for providing an output current to the second output terminal based on a signal of the first output terminal. The feedback module adjusts the bias current and the output current based on the first input signal and the second input signal. The output buffer has ability of switching the output voltage to be low level and high level in high-speed.

Output buffer and source driver using the same

A source driving circuit adapted to drive a display panel is provided herein. The source driving circuit includes a first output buffer and a second output buffer responsible for enhancing signals with different polarities respectively. As for the first output buffer, the first output buffer includes a first differential input stage, a first output stage and a second output stage. The first output stage includes a first level adjustment circuit and a first self-bias providing circuit. The first level adjustment circuit provides a first level voltage according to input signals received by the first differential input stage, such that the second output stage thereby provides a first charge current and a second charge current to output a first output signal based on the first level voltage. The first self-bias providing circuit provides a first biased voltage associated with one input signal to control the first level adjustment circuit to operate.

Source driving circuit with output buffer

An output buffer including a first differential input stage, a primary output stage, and a secondary output stage is provided herein. The first differential input stage respectively receives a first and a second input signals via a first and a second input terminals. The primary output stage includes a first and a second output stages. The first output stage provides at least one first level voltage according to the first and the second input signals, and the second output stage controlled by the first level voltage drives an output terminal of the output buffer to a target level. The secondary output stage includes a comparator and a third output stage. The comparator compares the induced currents in the first differential input stage, and thereby generates a control voltage. The third output stage controlled by the control voltage drives the output terminal of the output buffer to the target level.

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Tainan, Taiwan

Jia-Hui Wang