Sigma delta modulator with distributed prefiltering and feedback
US5055843A · kind A · utility
51Cited by
8References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1990 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Jan 31, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/454
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A separate filter circuit is inserted between the D/A converter and the summing junction in the feedback path of a conventional sigma delta modulator. This additional filter allows control of the quantization noise transfer function profile independently of the forward signal transfer function. By proper tailoring of the transfer functions a third or higher order modulator can be constructed without instability developing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.