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:
Sep. 29, 1981
Filed:
Aug. 13, 1979
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03G / ;
U.S. Cl.
CPC ...
330 86 ; 330254 ;
Abstract
A circuit for varying the gain of an amplifier circuit linearly in decibel by the use of a digital code signal varying linearly, wherein a resistance network to be connected between an amplifier having a fixed gain and an input or output portion for the amplification is connected and the gain of the amplifier as well as the values of resistance elements constituting the resistance network is set so that the transfer function of the amplifier circuit may become: ##EQU1## .