Filter with reduced element ratings and method
US5572162A · kind A · utility
15Cited by
4References
28Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1995 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | Jan 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/0461
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic filter for passing predetermined frequencies includes resistive and capacitive components that need not be rated to handle the input voltage. An input signal is converted to a second signal that is proportional to the logarithm of the input signal (and therefore of much smaller magnitude than the input signal), and then low, high, bandpass filtered with an RC filter. The filtered signal is reconverted to an output signal that is proportional to the inverse logarithm of the filtered signal. The filter may be embedded in a current mirror that may be used in telephone system subscriber line interface circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.