Method and arrangement for filtering with common mode feedback for low power consumption
US6407658B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 1999 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | May 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/045
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Improved common mode feedback is provided in differential amplifying-type gyrator filters. One specific implementation is directed to a signal-filtering circuit arrangement, comprising a transconductance cell, and a common mode feedback circuit including MOS-based transistors arranged to minimize loading on the transconductance cell. The transconductance cell has first and second current paths, each passing current between power terminals. The common mode feedback circuit includes a high-impedance circuit configured and arranged to compare a sampled common mode voltage to a reference voltage and to provide common mode feedback to the transconductance cell with minimized loading, and further includes a signal-sampling circuit for sampling the common mode voltage of the transconductance cell using a high impedance isolation arrangement of MOS-type transistors. The above implementation is especially useful in connection with integration of such filters as part of IC applications, while providing superior filter linearity and stopband rejection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.