An electronic device includes a multiplexer (MUX), a switching array and logic circuitry. The MUX includes multiple input ports and an output port, and is configured to receive, via the input ports, multiple input signals, and to output, via the output port, a selected signal among the input signals. The switching array is coupled to the input ports of the MUX and is configured to receive the input signals and to connect or disconnect between each input signal and a respective input port. The logic circuitry is electrically coupled to the switching array and to the MUX, and is configured to control the switching array to connect at least the selected signal that the MUX is outputting, and to disconnect all the input signals other than the at least selected signal.