Lapis Semiconductor Co., Ltd.

Lapis Technology Co., Ltd.

Hijiri Shirasaki

In a driver circuit, a bias voltage generation circuit generates and outputs a bias voltage for determining a bias current of an output amplifier. A memory stores a trimming code with which a slew rate of an output voltage outputted by the output amplifier is adjusted to fall within a target range set in advance. In an adjustment mode for adjusting the slew rate, a slew rate adjustment circuit adjusts the slew rate of the output amplifier based on a trimming code inputted from a shipping inspection device. Then, in a normal operation mode, the slew rate adjustment circuit changes a resistance value based on the trimming code stored in the memory to change a bias level of the bias voltage generation circuit and adjust the slew rate of the output amplifier.

Driver circuit for suppressing variations in slew rate

A display driver is provided which can prevent concentration of currents flowing into a display device and display a high-quality image without uneven luminance. A plurality of delayed clock signals used to apply a plurality of pixel driving voltages to data lines of the display device at respective different timings are generated by a DLL circuit including a variable delay circuit group constituted by variable delay circuits are connected in series, and a phase comparator that detects a phase difference of a delayed clock signal with respect to a reference clock signal and adjusts a delay amount of each of the variable delay circuits so that the phase difference converges to zero.

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Yokohama, Japan

Hijiri Shirasaki