| 摘要 |
An ISDN interface circuit is provided which is coupled to a terminal device via a transmission line and a reception line, the transmission line being formed of a pair of first and second wires, and the reception line being formed of a pair of third and fourth wires. The ISDN interface circuit includes a first resistor and a second resistor connected in series at a first node and between the first and second wires of the transmission line, and a third resistor and a fourth resistor connected in series at a second node and between the third and fourth wires of the reception line. The ISDN interface circuit also includes a D.C. power source connected to one of the first node, at which the first resistor and the second resistor are mutually connected in series and the second node, at which the third resistor and the fourth resistor are mutually connected in series. One of the first node and the second node, other than the above-mentioned one of the first node and the second node connected to the D.C. power source, is grounded. |
