| 摘要 |
PROBLEM TO BE SOLVED: To reduce reflection noise from multi-connection branch points. SOLUTION: In the case of transmission from a driver 11 to receivers 22,32, enable signal lines EN1, EN2, EN3 are respectively set to 'H', 'L' and 'L' levels. An 'H' level is given to a control terminal of an impedance conversion circuit 40 to set a pseudo earth plane 41 to be in a high impedance. Since the pseudo earth plane 41 has the high impedance, the static capacitance thereat is small and the impedance toward the receiver side when viewing from a branch point gets higher. Moreover, in the case of transmission from a driver 31 to receivers 12, 22, the enable signal lines EN1, EN2, EN3 are respectively set to 'L', 'L' and 'H' levels. An 'L' level is given to the control terminal of the impedance conversion circuit 40 to set the pseudo earth plane 41 to have an earth potential, the impedance of a branch signal line 60 gets small and a signal is sent from the driver 31 at a low loss. |
