Input sampling structure for delta-sigma modulator
US6147631A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Dec 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/496
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A signal processing circuit includes a main input sampling structure with an integrator operational amplifier and input lines including a switched capacitor. The input lines have switched connections to input signal lines and reference signal lines. A replica sampling structure is used in combination with the main input sampling structure to eliminate or reduce signal-dependent current that is drawn from the input signal line and the reference signal line. The replica sampler includes buffered input lines and switched capacitor of the input sampling structure but the capacitors have switched connections to the reference signal lines such that the connections have opposite polarity to the connections of the reference signal line to the input sampling structure. The replica sampler eliminates or reduces signal-dependent current from the reference signal lines. Buffering of the input lines in the replica sampler eliminates or reduces the signal-dependent current drawn from the input signal lines. The structure efficiently allows the use of a smaller capacitance for the same performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.