Patent · US Expired

Low noise level shifting circuits and methods and systems using the same

US6946890B1 · kind B1 · utility

5Cited by
1References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 11, 2004
Grant dateSep 20, 2005
Priority date
Expiry dateMar 20, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F3/45946
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A driver circuit includes an operational amplifier having an input and an output coupled by a feedback element. A voltage level shifter generates a voltage drop from the operational amplifier output to the operational amplifier input with a current source transistor setting a current controlling the voltage drop across the feedback element. A chopper circuit shifts flicker noise generated by the current source transistor to a higher frequency spectrum.

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