Novatek Microelectronics Corp.

Chicony Power Technology Co., Ltd.

Ying-Hsiang Wang

Cheng-Tsu Hsieh

Jung-Hsing Liao

Ke-Horng Chen

Tsung-Hau Chang

Yao-Hung Kuo

Chih-Wei Chang

Che-Hao Meng

Syang-Yun Tzeng

Ching-Wen Hou

Hao-Yuan Lin

Yu-Jen Lai

Sou-Chieh Chang

Ming-Yen Hsu

Ping Chen

Yun-Hsuan Yeh

Tai-Yin Wu

Chia-Lun Chang

Chao-Chang Chiu

An operational amplifier includes a first differential input pair, a first switch and a second switch. The first differential input pair includes a first input transistor and a second input transistor. The first input transistor has a gate terminal coupled to an output terminal of the operational amplifier. The second input transistor has a gate terminal. The first switch is coupled between the gate terminal of the first input transistor and the gate terminal of the second input transistor. The second switch is coupled between a first input terminal of the operational amplifier and the gate terminal of the second input transistor.

Capacitance decreasing scheme for operational amplifier

A source driver adapted to drive a display panel is provided. The source driver includes an output buffer and a slew rate adjustment circuit. An input terminal of the output buffer receives a driving voltage. An output terminal of the output buffer outputs an output signal adapted to drive the display panel. The slew rate adjustment circuit dynamically adjusts a slew rate of a rising edge of the output signal according to a first setting and dynamically adjusts a slew rate of a falling edge of the output signal according to a second setting independent of the first setting, such that the adjustment to the slew rate of the rising edge of the output signal is independent of the adjustment to the slew rate of the falling edge of the output signal.

Source driver and operation method thereof

An undervoltage detection circuit includes a voltage divider, a voltage-to-current (V-to-I) converter and a current comparator. The voltage divider divides a supply voltage to generate a divided voltage. The V-to-I converter converts the divided voltage into a first current based on a first V-to-I transfer function, and converts the divided voltage into a second current based on a second V-to-I transfer function different from the first V-to-I transfer function. The current comparator compares the first and second currents to generate a comparison signal that indicates whether the supply voltage is sufficiently large.

Undervoltage detection circuit

An electronic device includes a substrate and a display driver chip bonded on the substrate. The display driver chip includes a plurality of operational amplifiers, and each of the operational amplifiers has a first stage and a second stage. The first stage includes a first power input terminal. The second stage includes a first power input terminal and an output terminal for outputting an output voltage. The first power input terminal of the first stage is connected to a first metal trace of the substrate, and the first power input terminal of the second stage is connected to a second metal trace of the substrate. The first power input terminal of the first stage and the first power input terminal of the second stage are both provided with a first voltage level.

Electronic device and display driver chip

A source driving circuit, a display apparatus and an operation method are provided. The source driving circuit includes a reference voltage generating circuit, a plurality of compensation circuits, a gamma voltage generating circuit and a digital to analog converter. The reference voltage generating circuit is configured to generate a plurality of gamma reference voltages. The plurality of compensation circuits are coupled to the reference voltage generating circuit and configured to generate a plurality of compensated gamma reference voltages according to the plurality of gamma reference voltages and a voltage associated with a common voltage. The gamma voltage generating circuit is configured to generate a plurality of gamma voltages according to the plurality of compensated gamma reference voltages. The digital to analog converter is configured to generate a plurality of data driving voltages corresponding to image data according to the plurality of gamma voltages.

Source driving circuit, display apparatus and operation method of display apparatus

The present invention provides a driving circuit for a gamma voltage generator of a source driver. The gamma voltage generator includes a resistor string having a plurality of tap nodes, among which a plurality of first tap nodes are respectively connected to a plurality of first buffers. The driving circuit includes a second buffer, a digital-to-analog converter (DAC) and a control circuit. The second buffer is connected to a second tap node other than the plurality of first tap nodes among the plurality of tap nodes. The DAC is coupled to the second buffer. The control circuit, coupled to the DAC, is configured to receive a plurality of first control signals for the plurality of first buffers and calculate a second control signal for the DAC according to the plurality of first control signals.

Driving circuit for gamma voltage generator and gamma voltage generator using the same

The disclosure provides a slew rate enhancement apparatus that is connected to an operational amplifier that receives an input signal and generates an output signal according to the input signal for driving a pixel. The slew rate enhancement apparatus comprises a signal edge detector, a comparator, an adjustment unit. The signal edge detector is coupled to the operational amplifier and configured to detect a signal edge and outputting a difference signal corresponding to a difference between the input and output signals. The comparator is coupled to the signal edge detector to receive the difference signal and configured to generate a control signal according to the difference signal. The adjustment unit is coupled to the comparator to receive the control signal, and configured to couple a compensation signal generated by a current source to the operational amplifier according to the control signal to enhance a slew rate of the operation amplifier.

Slew rate enhancement circuit

A knee voltage detector for a flyback converter is provided. The knee voltage detector comprises a delay unit, for delaying an auxiliary related voltage for a specific period, to generate a delay signal; a subtracting unit, for generating a subtraction signal according to the auxiliary related voltage and the delay signal; a comparing unit, for generating a sampling signal when the subtraction signal indicates that a voltage difference between the auxiliary related voltage and the delay signal is greater than a threshold; and a sample and hold unit, for sampling the delay signal to generate a knee voltage according to the sampling signal when the voltage difference between the auxiliary related voltage and the delay signal is greater than the threshold.

Knee voltage detector

A waterproof, dustproof, breathing bolt includes a bolt body having a hollow shank with a breathing chamber and a cap member fixedly located at the top side of the hollow shank and defining therein an air passage in communication with the breathing chamber and one or a number of openings in communication between the air passage and the surroundings, and a waterproof breathing member made out of a metal material by powder metallurgy and set in between the breathing chamber and the air passage and having micro pores therein of size larger than air molecules but smaller than water molecules. Thus, the waterproof breathing member allows discharge of hot air out of the apparatus in which the waterproof, dustproof, breathing bolt is installed, but prohibits external water from entering the apparatus.

Growing community of inventors

Taipei, Taiwan

Ying-Hsiang Wang