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:
Dec. 04, 2001
Filed:
Aug. 25, 2000
Osamu Kitade, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In an REFS generation circuit included in a self refresh circuit of a DRAM, first to fifth N channel MOS transistors are connected in parallel with first to fifth fuses, and first to fifth P channel MOS transistors are connected in series with the first to fifth fuses. If the first to third and fifth fuses are blown to select a fourth clock signal and then the refresh performance is lowered, a third clock signal, for example, having a frequency shorter than the fourth clock signal is selected by rendering conductive only the third N channel MOS transistor and the third P channel MOS transistor of first to fifth N channel MOS transistors and the first to fifth P channel MOS transistors. Therefore, the refresh cycle can be shortened and a DRAM with a refresh failure can be repaired.