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. 10, 1985
Filed:
Aug. 17, 1983
Applicant:
Inventors:
Suk K Kim, Bridgewater, NJ (US);
Hanafy E Meleis, New Providence, NJ (US);
Assignee:
AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
307494 ; 307501 ; 307548 ; 307560 ; 307576 ; 330284 ;
Abstract
A high impedance is implemented in the input bias path of an integrated instrumentation amplifier. The implementation includes a normally on transistor switch. A signal from the output of the amplifier is used to turn the switch off to provide the requisite high impedance. Otherwise, the switch is on to provide low impedance for proper biasing. The circuit is adapted for encoded input signals such as occur in capacitive coupled credit card encoding circuits.