| abstract |
A modem unit is adapted to be coupled between a land or radio telephone line and a terminal equipment, and is provided with a modem circuit (8, 27, 85, 507) for modulating data received from the terminal equipment (250, 251, 506) and for demodulating data transmitted to the terminal equipment, and an isolation circuit (C1, C2, 34) for providing a DC isolation between the telephone line and the terminal equipment. The modem circuit and the isolation circuit are respectively provided on a single modem integrated circuit card. |