Method and apparatus for feedback signal generation in sigma-delta analog-to-digital converters
US7414557B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2006 |
| Grant date | Aug 19, 2008 |
| Priority date | — |
| Expiry date | Feb 15, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/464
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus taught herein provide a digital-to-analog converter (DAC) for use in a conversion feedback path of a sigma-delta type analog-to-digital converter (ADC). The DAC uses current pulse shaping to generate a conversion feedback signal in each feedback cycle of the ADC that provides a consistent charge transfer for accurate digital conversion and has a controlled current pulse shape. In one or more embodiments, the DAC includes a capacitor circuit for charge storage and transfer and a (series) resistive circuit having variable resistance for current pulse shape control. In at least one embodiment, current pulse control limits a peak current of the conversion feedback signal, thereby reducing DC power consumption and gain-bandwidth (GBW) and slew rate requirements of the ADC's integration amplifier, and limiting residual (ending) current in each feedback cycle, which yields commensurate gains in (feedback cycle) clock jitter insensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.