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:
Feb. 14, 1989
Filed:
Nov. 13, 1987
Applicant:
Inventors:
Thierry Fensch, Grenoble, FR;
Eric Compagne, Grenoble, FR;
Assignee:
Thomson Semiconducteurs, Paris, FR;
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379399 ; 375 71 ; 307279 ;
Abstract
A circuit is disclosed for the transmission of digital signals on a bifilary line, especially a telephone line. The circuit disclosed is a so-called S interface circuit which has to produce digital signals within certain set limits. The proposed circuit uses four differential amplifiers, each controlling an output transistor (N-channel MOS transistors and P-channel MOS transistors). The amplifiers receive feedback to maintain the overvoltages within acceptable limits. The invention applies especially to the setting up of integrated service digital telephone networks.