Patent · US Expired

Fast recovery amplifier

US4691174A · kind A · utility

5Cited by
1References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 19, 1986
Grant dateSep 1, 1987
Priority date
Expiry dateSep 19, 2006

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F2203/45146
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An amplifier includes first and second transistors having emitters connected to a first current source, feedback from the second transistor collector to its base being supplied through a base-emitter path of a first Darlington pair in series with a first diode. A second current source is connected to the first Darlington pair emitter. Third and fourth transistors have emitters connected to a third current source with feedback supplied from the fourth transistor collector to its base through a second Darlington pair and a second diode. The second Darlington pair emitter is connected to a fourth current source and resistively coupled to the first Darlington pair emitter. Constant currents are supplied to the second and fourth transistor collectors and an input voltage across the first and third transistor bases controls allocation of current between the first and second Darlington pair emitter-collector paths to produce a differential output current proportional to the input voltage when both Darlington pairs are on. When the input voltage is highly negative, the first Darlington pair turns off and a biasing circuit reverse biases the first diode to prevent the second transistor from…

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