Hitachi, Ltd.

Hitachi Vlsi Engineering Corp.

Tsuneo Ito

Masamichi Ishihara

Takashi Sato

Kunihiko Ikuzaki

Kenji Nagai

Shunji Shimada

Masafumi Kanagawa

Masayuki Yamashita

Tsuyoshi Saitou

Yoshio Noguchi

Mitsumasa Sato

An A/D converter apparatus comprises: a sampling signal generating means to generate an oversampling signal and an internal sampling signal; a converter means to convert an input analog signal into a digital signal in synchronism with the oversampling signal; and a decimator means to perform a specified decimation on the digital signal in synchronism with the internal sampling signal; whereby the sampling signal generating means maintains the frequencies of the oversampling signal and the internal sampling signal in a specified relationship.

A/D converter

The present invention relates to a transistor circuit, and more specifically to a static decoder circuit made up of a series circuit of a NOR logic gate circuit consisting of a plurality of MISFET's for receiving address signals through the gates, an inverter circuit for receiving the output of the logic gate circuit through the gate, a first MISFET for receiving the output of the logic gate circuit through the gate, and a second MISFET for receiving the output of the inverter circuit through the gate, wherein said NOR logic gate circuit and inverter circuit are connected to a ground terminal via a first switching MISFET which receives the control signals through the gate, and said series circuit is connected to a power supply terminal via a second switching MISFET which receives the control signals through the gate. According to the circuit of the present invention, said first and second switching MISFET's are rendered off by said control signals during the standby periods, such that the current pass is completely interrupted between the power supply terminal and the ground terminal in the decoder circuit, and the output of the decoder circuit is rendered to acquire the ground level.

MOS decoder logic circuit having reduced power consumption

A potential setting circuit is connected with a pair of common data lines which are made operative to receive data signals from memory cells. The potentials at the paired common data lines, which are forcibly set by the potential setting circuit, are set substantially at the middle level between the high and low levels of the data signals which are generated from the memory cells. As a result, the potential at the paired common data lines are changed within a relatively short time to the level of the data signals generated from the memory cells.

Data line potential setting circuit and MIS memory circuit using the same

A semiconductor memory device comprises an input address buffer circuit and a memory cell circuit which are constructed of static logic circuits, an address decoder circuit which is constructed of a dynamic logic circuit, a detector circuit which detects a change in an input address signal, and a pulse generator circuit which is started operating by an output signal of the detector circuit and which provides a clock signal for the dynamic logic circuit. Owing to the detector circuit and the pulse generator circuit, the semiconductor memory device operates without the necessity for any external clock signal.

Semiconductor memory device

In a n-channel (or p-channel) random access memory in which a plurality of memory cells are arranged in a matrix form in a p-type (or n-type) semiconductor substrate, clamping MOSFET's are connected between word lines provided for the associated rows of memory cells of the matrix and a reference potential to which gates the source electrodes of the information storing MOSFET's of the memory cells are connected. The clamping MOSFET has a lower threshold voltage than a row selecting MOSFET connected to the word line and clamps the word line when the word line is not selected, so that a delay in the read-out operation is eliminated or suppressed.

Random access memory

For driving a plurality of memory cells, a driver circuit, connected to the word driver line of the memory cells, includes a resistive connection, connected between the word line and ground potential, for preventing the potential of the word line from floating. The driver circuit includes an enhancement-type switching MOSFET and a depletion type resistor MOSFET connected in series. By virtue of the connection of a gate of the depletion type MOSFET, the depletion type MOSFET is always turned on so that whether or not the switching type enhancement MOSFET is turned on, the common connection between the switching MOSFET and the resistive MOSFET will always be at a prescribed potential thereby preventing the word driver line from floating.

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Kodaira, Japan

Tsuneo Ito