| 摘要 |
A switching circuit in which one out of a plurality of input channels is connectable to an output channel via one of the switching devices in the circuit. Each of the switching devices comprises an emitter-coupled pair of transistors which have a switchable current source in the emitter lead, the base of the first and the second transistor, respectively, of each pair being connected to one of the inputs and to the output, respectively. The output channel of the circuit comprises a transistor the emitter of which is connected to the output and the base to the interconnected collectors of the second transistors, this junction point being connected to a voltage-carrying terminal via a resistor. Via a selection switch which is connected to the switchable current sources only one of the input channels can at all times be connected through to the output channel. To increase the cross-talk attenuation, the non-conducting current sources are driven to the saturated state, non-conduction being ensured by limiting the maximum and minimum value, respectively, of the input signal with respect to the current source switching voltage.
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