VCO-based continuous-time sigma delta modulator equipped with truncation circuit and phase-domain excess loop delay compensation
US9634687B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2016 |
| Grant date | Apr 25, 2017 |
| Priority date | — |
| Expiry date | Mar 14, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/428
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A continuous-time sigma-delta modulator includes a VCO-based quantizer, a rotator, a truncation circuit and a digital-to-analog converter (DAC). The VCO-based quantizer is arranged to generate a thermometer code based on an input signal and a feedback signal. The rotator is coupled to the VCO-based quantizer, and is arranged to generate a phase-shifted thermometer code based on the thermometer code and a phase shift, and generate a rearranged thermometer code based on the phase-shifted thermometer code to comply with a specific pattern. The truncation circuit is coupled to the rotator, and is arranged to extract a most significant bit (MSB) part from the rearranged thermometer code. The DAC is coupled to the truncation circuit, and is arranged to generate the feedback signal according to at least the MSB part. Two alternative continuous-time sigma-delta modulators are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.