The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1999
Filed:
Jul. 28, 1997
Koichiro Ishibashi, Kodaira, JP;
Kunihiro Komiyaji, Hachioji, JP;
Kiyotsugu Ueda, Hachioji, JP;
Hiroshi Toyoshima, Hino, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi ULSI Engineering Corp., Tokyo, JP;
Abstract
A semiconductor memory device is provided which is able to supply data at high speed to a microprocessor (MPU) without being affected by the dispersion of power supply voltage, temperature and production process conditions. A semiconductor chip includes an address buffer, a decoder, a word driver, data lines, a sense amplifier, a main amplifier, an output buffer, and a PLL to which an external clock is applied. The PLL generates controls signals .PHI..sub.1 through .PHI..sub.7 with their phases shifted in turn, and supplies them to those internal circuits ranging from the address buffer to the output buffer. The PLL can control the phases of these control signals to be constant without being affected by the variations of temperature and power supply voltage. Thus, the internal circuits are precharged or equalized by the control signals, and then operated by the control signals to amplify data signal in turn. Therefore, the operating cycle time can be shortened as compared with the access time, and the access time can be kept constant.