| 摘要 |
PROBLEM TO BE SOLVED: To enable normal signal transmission even while using a coaxial cable of different characteristic impedance by providing a switch and changing the value of drive current of the coaxial cable by changing over the switch. SOLUTION: At the time of a drive current value Ia is suitable for the coaxial cable of characteristic impedance 50Ω, for example, a current changeover switch 13 is defined as a terminal (a) of a current setting circuit 19. Therefore, the current Ia flows to the coaxial cable. Besides, when using the coaxial cable of characteristic impedance 75Ω, the switch 13 is changed over to a terminal (b) of the circuit 19, and a drive current Ib corresponding to the impedance 75Ωis let flow. Thus, the amplitude of transmissive signal on the coaxial cable is made equal regardlessly of its characteristic impedance, and the signal can be normally transmitted. Therefore, one kind of transceiver can deal with plural transmission media and costs can be reduced.
|
