Switched capacitor filters with continuous time control
US5028893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1990 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Mar 21, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H19/004
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An ajustable switched capacitor circuit comprises a first stage, a second stage and a switched capacitor circuit coupling the output of the first stage to the input of the second stage. The operating parameters of the second stage are a function of the effective resistance of the switched capacitor coupling circuit. An attenuator interposed between the output of the first stage and the input of the switched capacitor coupling circuit controls the charging voltage of the switched capacitor coupler thereby controlling its effective resistance and parameters of the output stage. The signal loss through the attenuator is continuously adjustable responsive to an external control voltage to obtain continuous control of various output stage parameters. The output stage may comprise a filter having the parameters of its transfer function determined by the effective resistance of the switched capacitor coupling circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.