Discrete programming methodology and circuit for an active transconductance-C filter
US5666083A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1995 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Nov 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/0422
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit and method for adjusting a cutoff frequency of an active filter, such as a gm-C filter, which has a common mode feedback circuit for providing a bias signal may include plural common base stages having first inputs connected in parallel to a stage of the active filter and second inputs connected in parallel to an output from the common mode feedback circuit, and a capacitor connected to an output from each of the common base stages. The common base stages and their connected capacitors are selectively isolated from the filter output to adjust the cutoff frequency of the filter. The deselected common base stages are also isolated from the common mode feedback circuit and bias generator inputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.