Low pass filter
US6091289A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 18, 1998 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Jun 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
There is disclosed a low frequency filter. A low frequency cutoff filter includes a filter circuit having a capacitor connected between an input terminal and an output terminal and an active resistor connected to the output terminal, having a very large resistance, and a bias circuit having a negative feedback to set a biasing voltage of the active resistor to a desired value, thereby implementing the cutoff filter within a semiconductor chip as one set with the capacitor having a small capacitance. A low frequency pass filter includes an active resistor having a very large resistance, means for setting a biasing voltage of the active resistor to a desired value, and a capacitor connected between the output terminal and the ground. Therefore, the low pass filter can be integrated-circuited using even small capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.