Multi-bit ADC with sigma-delta modulation
US7142142B2 · kind B2 · utility
13Cited by
27References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 25, 2004 |
| Grant date | Nov 28, 2006 |
| Priority date | — |
| Expiry date | Feb 25, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/456
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An oximeter uses a sigma-delta modulator and a multi-bit ADC with PWM feedback enabling high precision multi-bit conversion. Demodulation is done in software, thus requiring only a single hardware path for both red and IR. Multiple capacitors are switched into the integrator in the sigma-delta modulator, with different capacitors for red, IR and dark signals, thus enabling the use of the single hardware path. A switching circuit at the input of the sigma-delta modulator acts as a sample and hold, controlled by the PWM feedback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.