Sigma delta modulator
US5311181A · kind A · utility
66Cited by
8References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 12, 1993 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | May 12, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/304
- 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. The modulator can also be constructed as a completely digital circuit and used as a noise shaping circuit in a digital digital-to-analog converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.