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:
May. 04, 1976
Filed:
Aug. 08, 1974
Applicant:
Inventor:
Peter Picard, Munich, DT;
Assignee:
Siemens Aktiengesellschaft, Berlin and Munich, DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 1791 / ;
Abstract
An integrated circuit construction for a telephone subscriber station having a microphone amplifier and a receiving audio amplifier is described. An impedance bridge replaces the conventionally used hybrid transformer. The aforementioned amplifiers are constructed in integrated circuit form as differential amplifiers, which are excited in parallel by separate reference voltages produced from two constant currents generated in a common source.