Patent · US Expired

Current amplifier circuit

US4990864A · kind A · utility

15Cited by
4References
23Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 7, 1990
Grant dateFeb 5, 1991
Priority date
Expiry dateFeb 7, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F3/343
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An amplifier circuit (10) is provided which comprises a first transistor (12) and a second transistor (14). A current buffer circuit (16) is coupled to the basis of the transistors (12, 14) to provide base drive current. A voltage proportional to absolute temperature, V.sub.PTAT, is applied between the emitters of the transistors (12,14). An input current is received by the transistor (12) and an output current is generated by the transistor (14). The output current I.sub.out is amplified with respect to the input current I.sub.in by a gain factor which is substantially independent of temperature considerations. Circuitry is provided for altering the value of the voltage proportional to the absolute temperature, V.sub.PTAT, such that the gain of the amplifier circuit (10) is programmable.

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