| 摘要 |
PURPOSE:To obtain a small-sized, economical telephone set with high performance and high-level function, by packaging a circuit which has originating, incoming, and calling function in a one-chip LSI, and using the circuit in common. CONSTITUTION:A transmitted signal inputted from a transmitter 7 is passed through an amplifying circuit 7a, transmission system loss circuit 7p, and interface circuit 7b, power-amplified by a line output circuit 5, and sent out from terminals 1 and 2. Further, the transmitted signal from the transmitter 7 is sent to a receiving amplifying circuit after side-tone balance is kept by resistances R1 and R2 and a balancing network 14. Then it is passed through a line and a received signal appearing between the terminals 1 and 2 is voltage-divided by the network and resistances R1 and R2 to send the output to the receiving amplifying circuit through a coupling capacitor C5, heating it through a receiver 8. Then, a dial signal generated by a dial signal synthesizing part 6b corresponding to push-button information is inputted through a dial system loss circuit 6p to an LPF6c and then sent out of the circuit 5 to the line side. |
