Abstract: A Gunn-effect device originated from a Gunn-triode wherein electrodes are added between gate and anode for receiving high and low potentials representing states 1 and 0 of a binary code. In a normal Gunn-triode a very short pulse on the gate produces a dipole domain which is propagated to the anode within a time of the order of the nanosecond. In the present device, under each finger brought temporarily to a low potential, there is produced a space charge which induces a negative pulse in the anode current of the Gunn device upon the passage of a dipole domain under the finger. Consequently, a series of successive pulses corresponds to a combination of simultaneous binary states. A digital converter using this device is proposed for converting simultaneous binary signals into successive binary signals.