Patent · US Expired

High input impedance circuit

US4602172A · kind A · utility

4Cited by
5References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 10, 1983
Grant dateJul 22, 1986
Priority date
Expiry dateMay 10, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K5/1534
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A high input impedance circuit having a first differential circuit consisting of a pair of NPN transistors and a second differential circuit consisting of a pair of PNP transistors, is disclosed. One input terminal of the first differential circuit is connected to one input terminal of the second differential circuit. The other input terminal of the first differential circuit is connected to the other input terminal of the second differential circuit. A signal is supplied through a capacitor to one input terminal for eliminating a DC component of the signal. A DC biasing circuit for biasing the first and second differential circuits is connected to the other input terminal. First and second current source circuits are connected to the first and second differential circuits respectively.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.