| 摘要 |
PROBLEM TO BE SOLVED: To obtain a circuit which uses a small number of components capable of saving space and has less waveform deterioration by composing of the circuit of an input buffer, a selector with high input resistance, and a terminating circuit which is provided at a signal transmission line end matching the characteristic impedance of a signal transmission line decreased because of the insertion of the selector. SOLUTION: Input signals INi (i=1 to m) which are high-frequency pulse signals are inputted to input buffer amplifiers 10i (i=1 to m), and positive and negative differential high-frequency pulse signals are outputted to signal transmission lines 12i (i=1 to m). Signal transmission line 12i sequentially connect the high-frequency pulse signals to selectors 17h (i=1 to m) at equal intervals. The input terminals of the selectors 17h have a nearly infinitely high resistance and a specific capacity value and select one of (m) kinds of input signal INi. After the high-frequency pulse signals are connected to the necessary number of selectors 17h, they are terminated by matched terminating circuits 11i (i=1 to m). |
