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. 18, 2001
Filed:
May. 12, 2000
Atsushi Hirabayashi, Tokyo, JP;
Kosuke Fujita, Kanagawa, JP;
Kenji Komori, Kanagawa, JP;
Norihiro Murayama, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
A high impedance circuit capable of operating at a low voltage without narrowing the dynamic range is provided, which includes a first and a second transistors forming differential-pair type circuit, a third and fourth transistors, a pair of collector resistance elements, a resistance element and a pair of current source circuits. The third and the fourth transistors serve as emitter follower circuits which also functions as a DC shift with respect to the differential-pair type circuit, as well as buffer circuits for heightening an input impedance of the first and the second transistors looked from the base side of the third and the fourth transistors. The current flowing in the resistance element is made current-fedback with respect to the resistance elements by the third and the fourth transistors. The input impedance is determined as Z,=V,/ i,=(R,×R,)/(R,−R,), and when R,=R,, the high impedance circuit becomes infinite impedance.