Semiconductor Components Industries, LLC

Sanyo Electric Co., Ltd.

Mamoru Yamaguchi

Tetsuya Tokunaga

Norikazu Katagiri

Kensuke Goto

Hiroyuki Arai

Takeshi Kimura

Tomoshi Yoshida

Ryouichi Ando

Hiroyuki Nakamura

A liquid-crystal-driving circuit includes: a plurality of resistors connected in series between a first and second potentials; one or more voltage follower circuits to impedance-convert one or more intermediate potentials between the first and second potentials, to be outputted, respectively, the intermediate potentials generated at one or more connection points between the resistors, respectively; a common-signal-output circuit to supply common signals to common electrodes of a liquid-crystal panel, respectively, the common signals each being at the first and second potentials, and the intermediate potentials; and a segment-signal-output circuit to supply segment signals to segment electrodes of the panel, respectively, the segment signals each being at the first and second potentials, and the intermediate potentials according to the common signals, the segment-signal output circuit to change the potentials of the segment signals in a ramp form, at least if the potentials of the segment signals are changed with a maximum-possible-potential difference.

Liquid crystal driving circuit having a common-signal output circuit and a segment-signal output circuit and method

A liquid-crystal-driving circuit includes: resistors connected in series between first and second potentials lower than the first potential; one or more voltage follower circuits to impedance-convert one or more intermediate potentials between the first and second potentials, to be outputted, respectively, the intermediate potentials generated at one or more connection points between the resistors, respectively; a common-signal-output circuit to supply common signals to common electrodes of a liquid crystal panel, respectively, the common signals being at the first, second, or one or more intermediate potentials in a predetermined order; and a segment-signal output circuit supplies segment signals to segment electrodes of the liquid crystal panel, respectively, the segment signals being at the first and second potentials, or the intermediate potentials according to the common signals, wherein the segment-signal output circuit increases impedances of the segment signals only for a first period when the of segment signals potentials are switched.

Liquid crystal driving circuit

A frequency adjustment circuit that maintains a target frequency even when frequency adjustment data of zapping circuit is changed by an external noise is offered. The frequency adjustment circuit includes a reset signal generation circuit, a frequency adjustment data latch circuit that latches and retains the frequency adjustment data ZPand ZPgenerated by a first zapping circuit and a second zapping circuit based on a latch clock ZCLK and a latch clock generation circuit that generates the latch clock ZCLK. The reset signal generation circuit generates a periodic reset signal ZRES that is synchronized with a rise of an enable signal EN generated from an interface circuit. The latch clock generation circuit generates the latch clock ZCLK that is synchronized with a fall of the enable signal EN.

Frequency adjustment circuit

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Gunma-ken, Japan

Mamoru Yamaguchi