| 摘要 |
PURPOSE:To realize an IC or LSI formation by providing a clamp element at an optional point between the outside of a capacitor and an input terminal of an amplifier, and a point with reference potential. CONSTITUTION:A clamp circuit 15 consists of two diodes 16, 17 connected reversely in parallel, and one of them is earthed between an impedance circuit 6 and an amplification circuit 9 to be equipped in a line. In case a multi- frequency signal is generated in the subscriber's circuit L, the reverse input terminal of an operational amplifier 10 is almost kept at a ground potential due to low impedance of a clamp circuit 15, and the charge charged in a capacitor 7 is discharged through diodes 16, 17 of the clamp circuit 15, so a momentary break time of the multi-frequency signal can be shortened. That is, a momentary break time of the signal is shortened by addition of a clamp element to have a good character as a subscriber's circuit of switchboard and the IC and LSI formation are realized. |
