| 摘要 |
PURPOSE:To obtain a bidirectional signal line extension circuit which can be adapted flexibly to system configuration and reduces the production cost, by connecting the output of a driver circuit, which controls line extension, to one of two systems of bidirectional signal lines. CONSTITUTION:A DC level detecting circuit 4 sets an output F to logical ''1'' if a differential voltage between inputs A and B is higher than an input reference voltage signal REF, and the circuit 4 sets the output F to logical ''0'' if said differential voltage is lower than the input reference voltage signal REF. Consequently, a differential output driver 5 connected to an output G of an inverter 6 is set to the not enable state when differential output drivers 1 and 1' are in the enable state, and the driver 5 is set to the enable state when drivers 1 and 1' are in the not enable state. Thus, differential output drivers 1 and 1' of a transmission/reception control part and the differential output driver 5 of an extension circuit part connected to differential output drivers 1 and 1' are prevented from being set to the enable state simultaneously. |
