Differential switched-capacitor sigma-delta modulator
US5001725A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1989 |
| Grant date | Mar 19, 1991 |
| Priority date | — |
| Expiry date | May 19, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/454
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A fully differential sigma-delta signal processor for use in high-speed voiceband or higher-frequency applications. The processor receives the two polarities of a differential input signal and passes them to a differential-amplifier integrator through a switched sampling capacitor arrangement. The capacitors are each alternately and concurrently switched back and forth between the two signal paths for the two polarities of the input signal responsive to a clock signal in such a manner as to sample and integrate the input signal at an effective signal transfer rate of at least twice the clock frequency. An analog-to-digital converter defines a digital feedback-control signal characteristic of the integrator output signal. A second switched-capacitor arrangement selectively applies a feedback signal to the integrator inputs, responsive to the digital control signal, at a switching rate comparable to the effective signal transfer rate through the integrator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.