Patent · US Expired

Differential amplifier circuit

US4855686A · kind A · utility

1Cited by
1References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 2, 1988
Grant dateAug 8, 1989
Priority date
Expiry dateJun 2, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F2203/45674
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

Disclosed is a differential amplifier circuit which includes a first NPN transistor, a second NPN transistor, a current source connected to the emitters of the first and second NPN transistors, a first PNP load transistor having a collector connected to the collector of the first NPN transistor, a second PNP load transistor having a collector coupled to the collector of the second NPN transistor, and an FET having a gate connected to the collector of the first NPN transistor, and a source connected to the bases of the first and second PNP load transistors. A DC input current of the FET is substantially zero, and is designed to absorb a current corresponding to the gate potential of the FET, from the bases of the first and second PNP load transistors.

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