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. 12, 1995
Filed:
Mar. 27, 1992
Applicant:
Inventor:
Futao Yamaguchi, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ; G06G / ;
U.S. Cl.
CPC ...
327552 ; 327558 ; 327560 ; 327563 ; 327310 ; 327336 ;
Abstract
An active filter circuit has differential transistors having first conductivity type bipolar transistors and load transistors having second conductivity type bipolar transistors. A connecting node between the differential transistors and the load transistors is driven by a middle electric potential. Voltage dependent characteristics of earth capacitance including parasitic capacitances parasitic to the differential transistors and the load transistors can be kept constant by offsetting the voltage dependent characteristics of the parasitic capacitances. It is thereby possible to make the active filter circuit small in size and the consumed electric power reduced.