Patent · US Expired

Front end of an operational amplifier

US4636744A · kind A · utility

15Cited by
9References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 1, 1985
Grant dateJan 13, 1987
Priority date
Expiry dateOct 1, 2005

Classification

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

Abstract

The front end of an operational amplifier having an improved controlled slew rate and high gain current output capabilities. The amplifier includes a slew enhancement or large signal stage connected in parallel to a normal front end or small signal stage. The small signal stage supplies a transconductance output which is approximately linearly related to the input until its slew rate limit. The slew enhancement stage is designed to provide slew current when the small signal stage reaches its slew rate limit, thereby providing an increased output current response to an increasing differential input voltage beyond the slew rate of the small signal stage. Two pair of differential amplifiers are used in both a large and small signal stage as well as an improved output stage comprising of current mirrors.

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