Read-out photodiodes using sigma-delta oversampled analog-to-digital converters
US5142286A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1990 |
| Grant date | Aug 25, 1992 |
| Priority date | — |
| Expiry date | Oct 1, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/414
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Sigma-delta analog-to-digital conversion is used in sensing apparatus that generates a digital signal descriptive of light energy received by a photosensor, such as one of a plurality of photosensors that together receive various elements of a radiant-energy image. A preamplifier generates an analog output signal responsive to the photocurrent of the photosensor, which analog output signal is undesirably accompanied by wideband noise. The analog output signal is supplied to a sigma-delta analog-to-digital converter, the decimation filter of which not only suppresses in the digital signal a component arising from the quantization noise from the sigma-delta modulator portion of the analog-to-digital converter, but also suppresses a component arising from remnant wideband noise from the preamplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.