Modem having an improved line interface circuit, in particular for a computer
US5506868A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1994 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Aug 25, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Circuitry is described for providing a telephone line interface circuit of a MODEM for a computer with an AC impedance and DC voltage/current characteristics required by a given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network. The given type telephone network provides an identification code representative of the required AC impedance and DC voltage/current characteristics. The circuitry comprises a plurality of impedance components that, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit. A plurality of terminals are coupled to receive a plurality of control signals associated with the identification code. A switching logic is coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the requ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.