Lapis Semiconductor Co., Ltd.

Lapis Technology Co., Ltd.

Hideki Masai

Hideaki Hasegawa

A charge pump circuit includes: first and second capacitors; a first switch element group turned on and off by a first clock signal and connecting a first voltage supply line and the first capacitor when turned on; a second switch element group turned on and off by the first clock signal and connecting a second voltage supply line and the second capacitor when turned on; and a third switch element group turned on and off by a second clock signal and connecting a voltage output line and the first and second capacitors when turned on. A control circuit controls a timing of a signal change of a first enable signal so that the signal levels of the first and second clock signals are fixed when the first and second switch element groups change from off to on, in response to stopping oscillating the first and second clock signals.

Voltage generation circuit and control device

A first latch retrieves a pixel data piece for each one horizontal scanning period of a video data signal and holds the pixel data piece as a first pixel data piece. A second latch retrieves the first pixel data piece from the first latch at a timing when the retrieval by the first latch is completed and holds the first pixel data piece as a second pixel data piece. An interpolation data generating unit obtains the first pixel data piece and the second pixel data piece and generates an interpolation data piece. A third latch alternately performs a retrieval of the second pixel data piece and a retrieval of the interpolation data piece, and sequentially outputs the retrieved data piece as a third pixel data piece. A gradation voltage output unit outputs the gradation voltage signal based on the third pixel data piece.

Display driver and display device

A semiconductor device includes a signal processing circuit configured to generate an output signal, an output pad, an output line connecting the signal processing circuit to the output pad, the output signal from the signal processing circuit being output from the output pad through the output line, a shorting pad formed in the output line, a switch connected between the shorting pad and the output pad, and configured to connect the signal processing circuit to the output pad when the switch is on, and disconnect the signal processing circuit from the output pad when the switch is off, and a wiring line connecting the shorting pad to the output pad.

Semiconductor device, semiconductor chip, and test method for semiconductor chip

A display driver is configured to drive a display device according to a video signal. The display signal includes a plurality of first to N-th output amplifiers (N is an integer greater than two) and an output electrical current capacity setting portion. The first to N-th output amplifiers are configured to amplify first to N-th gradation voltages a representing brightness level per pixel according to the video signal, so that the first to N-th output amplifiers obtain first to N-th pixel drive voltages. Further, the first to N-th output amplifiers are configured to output the first to N-th pixel drive voltages to the display device. The output electrical current capacity setting portion is configured to set an output electrical current capacity of each of the first to N-th output amplifiers individually or in a group of a plurality of output amplifiers.

Growing community of inventors

Yokohama, Japan

Hideki Masai