Patent · US Expired

Delta sigma modulator circuit for an analog-to-digital converter

US4772871A · kind A · utility

46Cited by
1References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 7, 1987
Grant dateSep 20, 1988
Priority date
Expiry dateMay 7, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M3/42
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

In a delta-sigma modulator for an A/D converter for modulating an analog input signal to produce a modulated signal of a digital form, a first integrator produces a first integral signal indicative of an integral of the difference between the analog input signal and feedback signal, a first delay element delays the first integral signal by one sampling period, a second integrator produces a second integral signal indicative of an integral of the difference between the output of the first delay element and the feedback signal, a first quantizer produces a two-level signal "1" or "0" depending on whether or not the second integral signal is greater than a predetermined reference, and a second quantizer produces a two-level signal "1" or "0" depending on whether or not the first integral signal is greater than a predetermined reference. An output digital signal is produced in accordance with the outputs of the first and the second quantizers. The feedback signal is also produced in accordance with the outputs of the first and the second quantizers.

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