Renesas Technology Corp.

Hitachi Device Engineering Co., Ltd.

Kazuya Endo

Naoki Miyamoto

Yoshikazu Yokota

Toshio Mizuno

Kazuo Ookado

Takayuki Nakaji

Takatoshi Uchida

Goro Sakamaki

Takesada Akiba

Yasushi Kawase

Toshikazu Tachibana

Yoshitaka Iwasaki

A semiconductor circuit with the reduced scale of circuitry and a semiconductor integrated circuit chip which is obtained by integrating the semiconductor circuit and enables chip size reduction are provided. For this purpose, a two-decode method is used. The method uses: a pre-decode circuit comprising a first decoder of the preceding stage which decodes an arbitrary bit of an address signal of eight bits and a second decoder of the preceding stage which decodes the remaining bits; level conversion circuits which shift the output of the pre-decode circuit; and post-decode circuits which decode the decode outputs of the decoders in the pre-decode circuit, level-converted through the level conversion circuits.

Semiconductor circuit

There is to be provided a liquid crystal drive controller with a built-in power supply circuit wherein latch-up is made difficult to arise even if one amplitude level of the segment line drive voltage is set to the ground potential and the levels of other liquid crystal drive voltages are determined accordingly. A semiconductor integrated circuit with a built-in power supply circuit, wherein a negative voltage generated in a power supply circuit is applied to a substrate or a well region as a bias voltage, is provided with a switch for temporarily applying the ground potential to the substrate or well region to be biased with the negative voltage at the time of starting up the power supply circuit.

Semiconductor integrated circuit with voltage generation circuit, liquid crystal display controller and mobile electric equipment

By implementing reduction in power of common electrode voltages applied from a power source of a liquid crystal drive device to common electrode interconnects of a liquid crystal display panel, respectively, reduction in power consumption of the liquid crystal display panel as a whole is attained. A VCOM operation waveform in a charging process from a second voltage VCOML to a first voltage VCOMH shows that a charging current Icha represents the sum of a charging current from VCOML to a reference voltage VCI, Icha=Cp (VCI&#x2212;VCOML)/&#x394;t, and a charging current from the reference voltage VCI to the first voltage VCOMH, Icha=Cp (VCOMH&#x2212;VCI)/&#x394;t. Accordingly, power consumed by Ichais the reference voltage VCI&#xd7;Icha, and power consumed by Ichais VCI&#xd7;Icha&#xd7;2. Meanwhile, a discharging current at a time of discharging from the first voltage VCOMH to the second voltage VCOML is the sum of a discharging current from the first voltage VCOMH to the ground potential GND, Idis=Cp (VCOMH&#x2212;GND)/&#x394;t, and a discharging current from the ground potential GND to the second voltage VCOML, Idis=Cp (GND&#x2212;VCOML)/&#x394;t. Now, if converted in terms of power consumed at the reference voltage VCI, since Idisrepresents discharge to GND, power consumption thereby becomes zero. Then, consumed power due to the discharging current from the ground potential GND to the second voltage VCOML, Idis, is VCI&#xd7;Idis

Liquid crystal drive device

Growing community of inventors

Higashimurayama, Japan

Kazuya Endo