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. 29, 1987
Filed:
Aug. 12, 1986
Keizo Aoyama, Yamato, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A semiconductor device having a circuit for regulating the external power supply voltage applied to the chip. When numerous chips are used in an electronic circuit having an external power supply voltage, variations in the electrical characteristics, such as the total power supply current, of each chip, become a problem. According to the present invention, variations in the electrical characteristics can be reduced by compensating the chip-to-chip fluctuations of the conductance of transistors (FETs) contained in an inner circuit disposed on the chip. A dummy transistor having a relatively short channel length is employed as a circuit for detecting the electrical characteristics of the transistors formed on the chip. The voltage drop across the dummy transistor is employed as a representative signal since it is sensitive to variations in the characteristics of the FETs contained in the inner circuit. Regulation of the power supply voltage is performed by a regulating device, usually a transistor, connected in series between the external power supply and the inner circuit. The representative signal is amplified by a regulating signal generating circuit whose output voltage is applied to the regulating device, thereby controlling the conductance of the regulating device.