Hitachi, Ltd.

Hitachi Vlsi Engineering Corp.

Hitachi Microcomputer Eng. Ltd.

Hitachi Microcomputer Hitachi, Ltd. & Engineering, Ltd.

Masaaki Kubotera

Osamu Minato

Katsuro Sasaki

Shoji Hanamura

Makoto Saeki

Hideaki Nakamura

Sho Yamamoto

Kiyotsugu Ueda

Yasuo Yoshitomi

Takao Oono

Information read out from a memory cell of a static type semiconductor memory is subjected to multi-stage sense amplification in an initial stage sense amplifier, a post-stage sense amplifier and a main amplifier and then transmitted to the input of an output buffer circuit. Since an equalizing circuit is connected to the complementary inputs of each stage of the multi-stage sense amplifier, an inverse information read operation can be executed at high speed. Initially, the initial stage sense amplifier, the post-stage sense amplifier and the main amplifier are controlled to operate in high amplification gain conditions so as to execute high speed sense amplification and thereafter controlled to operate in such low power consumption conditions that the read-out information output obtained by the high speed sense amplification will not disappear.

Static type semiconductor memory

Information read out from a memory cell of a static type semiconductor memory is subjected to multi-stage sense amplification in an initial stage sense amplifier, a post-stage snese amplifier and a main amplifier and then transmitted to the input of an output buffer circuit. Since an equalizing circuit is connected to the complementary inputs of each stage of the multi-stage sense amplifier, an inverse information read operation can be executed at high speed. Initially, the initial stage sense amplifier, the post-stage sense amplifier and the main amplifier are controlled to operate in high amplification gain conditions so as to execute high speed sense amplification and thereafter controlled to operate in such low power consumption conditions that the read-out information output obtained by the high speed sense amplification will not disappear.

Static type semiconductor memory with multi-stage sense amplifier

An MOS static type RAM has a memory cell array comprising of a plurality of static type memory cells arranged in matrix, a plurality of data lines connected to the data input-output terminals of the respective memory cells and a plurality of word lines connected to the selection terminals of the respective memory cells. Data line load circuits are disposed between the power terminal of the circuit and the data lines. Each data line load circuit is kept at a relatively high impedance in the data write-in operation, and at a relatively low impedance in the data read-out operation. The use of the data line load circuits comprised of such variable impedance circuits can speed up the operating speed of the RAM and can accomplish lower power consumption.

MOS static type RAM having a variable load

An MOS static type RAM has a memory cell array comprising a plurality of static type memory cells arranged in matrix, a plurality of data lines connected to the data input-output terminals of the respective memory cells and a plurality of word lines connected to the selection terminals of the respective memory cells. Data line load circuits are disposed between the power terminal of the circuit and the data lines. Each data line load circuit is kept at a relatively high impedance in the data write-in operation, and at a relatively low impedance in the data read-out operation. The use of the data line load circuits comprised of such variable impedance circuits can speed up the operating speed of the RAM and can accomplish lower power consumption.

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Koganei, Japan

Masaaki Kubotera