Data acquisition system using delta-sigma analog-to-digital signal converters
US6657571B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2001 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Jun 5, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/452
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A delta-sigma A/D converter includes a delta-sigma modulator having an integrating amplifier dispose within the loop of the modulator so that the input of the modulator can be connected to receive relatively low level input currents, and so as to improve DC stability. The modulator is specifically adapted for IC implementation for use in a DAS of a CT scanner so that the current output of a detector of the scanner can be connected directly to the input of the modulator of the converter. The noise shaping characteristics are shaped so as to provide an improved frequency response with minimal spillover. Noise shaping of the converter is provided throughout the dynamic range of the current outputs of CT scanner detectors so as to compensate for the poorer S/N for low input currents. The preferred converter also includes a unique digital filter transfer function, with finite impulse response (FIR) filter characteristics, optimized for CT-DAS applications and having excellent characteristics in the frequency domain and the time domain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.