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. 02, 1980
Filed:
Jul. 22, 1977
Applicant:
Inventor:
Rodney J Lawton, Swindon, GB;
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
307264 ; 307230 ; 307237 ; 333 14 ; 333 / ; 333217 ;
Abstract
This disclosure relates to an electronic circuit which has a controllable impedance. This type of circuit is well suited for application in noise suppression circuits or in signal compression/expansion circuits. The circuit has two stages. The first stage is a voltage to current converter. The second stage is a variable gain current amplifier. The output of the second stage is connected by a feedback loop to an input of the first stage. The circuit has a variable impedance which can be controlled by an external signal. The imput impedance of the circuit is linearly related to the applied control signal.