Patent · US Expired

Auto-zero circuit

US7348824B2 · kind B2 · utility

6Cited by
2References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 7, 2005
Grant dateMar 25, 2008
Priority date
Expiry dateMar 7, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F3/45973
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

An auto-zero circuit is disclosed. The auto-zero circuit includes a first set of circuits for implementing a first auto-zero phase and a second set of circuits for implementing a second auto-zero phase. The first set of circuits includes a first differential amplifier and a first feedback path coupled between an output of the first differential amplifier and an input of the first differential amplifier. The second set of circuits includes a second differential amplifier and a second feedback path coupled between an output of the second differential amplifier and an input of the first differential amplifier, where the second feedback path includes an attenuation capacitor for reducing charge injection error and noise error of the auto-zero circuit and a holding capacitor for holding a voltage to be used to correct charge injection error introduced by the first feedback path.

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