Method for varying the interpolation ratio of a digital oversampling digital-to-analog converter system and apparatus therefor
US5313205A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1993 |
| Grant date | May 17, 1994 |
| Priority date | — |
| Expiry date | Apr 6, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/508
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital oversampling digital-to-analog converter system includes an interpolator, a sigma-delta modulator, a digital-to-analog converter and a low pass filter. The interpolator receives a digital input signal and upsamples the input signal by certain upsampling factor. The upsampled signal is processed by the sigma-delta modulator, converted to an analog signal by the digital-to-analog converter and then filtered by the low pass filter. The interpolator includes control circuitry, preferably a central processor, which controls the upsampling factor and increases the upsampling factor upon a decrease in the frequency of the input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.