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:
Aug. 06, 1996
Filed:
Apr. 07, 1994
Masaaki Kuwagata, Kawaguchi, JP;
Ryosuke Matsuo, Yokohama, JP;
Keiji Maruyama, Kawasaki, JP;
Naokazu Miyawaki, Yokohama, JP;
Hisashi Ueno, Oita, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor integrated circuit includes a bias voltage regulation circuit having variable resistors which are provided between voltage output circuits of higher and lower potential sides and changes corresponding to a specified condition such as V.sub.CC and a temperature. The variable resistors and bias voltage output circuits form a V.sub.CC divider, and the variable resistors properly regulate a bias voltage supplied to an oscillation circuit corresponding to each of the specified conditions. Accordingly, if the oscillation circuit is used in an automatic refresh circuit of a PSRAM, an increase of a refresh operation frequency is suppressed regardless of an increase in V.sub.CC. Since a temperature depending variable resistor causes a resistance value to be reduced by the predetermined characteristics against the temperature increase, it is possible to set an oscillation frequency to provide a desired pause for guarantee of circuit operation. It is possible to provide a ring oscillator having a low dependency of the oscillation frequency on a power source voltage and a temperature characteristic, thereby decreasing its current consumption.