Novatek Microelectronics Corp.

Wei-Hsiang Hung

Chia-Hung Lin

Ji-Ting Chen

Xie-Ren Hsu

Chia-Wei Su

Shun-Hsun Yang

Li-Tang Lin

Ying-Zu Lin

Chia-Hsun Kuo

An operational amplifier applicable to a display device is provided. The operational amplifier having multiple output stages. The operational amplifier includes an input stage, an output stage selection module and a plurality of output stages. The output stage selection module is coupled to the input stage. Each of the output stages is coupled to the output stage selection module and is coupleable to drive a corresponding one of a plurality of loads. The output stage selection module is configured to selectively couple or discouple each of the output stages respectively to the input stage according to a plurality of selection signal. Furthermore, a load driving apparatus and a grayscale voltage generating circuit are also provided.

Operational amplifier, load driving apparatus and grayscale voltage generating circuit

A load driving apparatus for driving a plurality of loads is provided. The load driving apparatus includes an output stage module, a load driving module, and an output stage selection module. The output stage module includes a plurality of output stages. Each of the output stages is coupled to a corresponding one of the loads. The load driving module is coupled to the output stage module and outputs a driving signal to drive one of the loads through the output stage module. The output stage selection module is coupled between the output stage module and the load driving module and selects one of the output stages in the output stage module, so that the load driving module drives the load which is coupled to the selected output stage through the selected output stage. Furthermore, a grayscale voltage generating circuit including the foregoing load driving apparatus is also provided.

Load driving apparatus and grayscale voltage generating circuit

A display driver, which comprises: a first predetermined voltage level providing apparatus, for providing a first predetermined voltage level group comprising at least one first predetermined voltage level; a first image data providing apparatus, for outputting a first image data; and a detection controlling circuit, for determining if an output terminal of the first image data providing apparatus is pre-charged to the first predetermined voltage level according to a relation between an absolute value of a voltage level of the first image data and an absolute value of the first predetermined voltage level.

Display driver and display diving method

An adaptive amplification circuit is provided, which includes an operational amplifier comprising a variable bias current source for providing a variable bias current for the operational amplifier, an equivalent circuit of the operational amplifier for receiving an input voltage and generating an output voltage according to the input voltage, and a bias control unit for generating a bias control signal to the variable bias current source according to the output voltage so as to adjust the variable bias current.

Adaptive amplification circuit

An operational amplifier includes an input stage, an output stage, an output enable switch, an internal capacitor, a coupling effect reduction circuit. The input stage provides an intermediate signal according to an input signal. The output stage, including an output node, provides a driving signal according to the intermediate signal. The output enable switch is turned on during an output enable period, having a start time point, to drive a load with the driving signal. The internal capacitor is coupled between the input stage and the output stage. The coupling effect reduction circuit, coupled between the internal capacitor and the output node or between the internal capacitor and the input stage, is turned off during an operational period starting from the start time point, to prevent coupling charge generated when the output enable switch is turned on from affecting operational voltage levels of the input stage.

Operational amplifier

An adaptive amplification circuit is disclosed, which includes an operational amplifier including a variable bias current source for providing a variable bias current for the operational amplifier, a simulation unit for simulating operational characteristics of the operational amplifier and transforming a simulation input voltage to a simulation output voltage, and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current.

A bias current control method for an operational amplifier is disclosed, which includes detecting a slew rate operating signal, determining signal period length of the slew rate operating signal to generate a determination signal, and generating a high bias modulation signal or a low bias modulation signal to the operational amplifier according to the determination signal and the slew rate operating signal.

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Hsinchu, Taiwan

Wei-Hsiang Hung