A rapid SFQ one-way buffer (13, 1, 4, 5, 15, 2 & 9), is combined with a Josephson transmission line (17,3, 19, 16, 21 & 4) that is lightly loaded (R.sub.L) to provide a superconductor driver capable of producing double flux quantum output pulses. Each SFQ pulse applied to the input of the one-way buffer propagates through the Josephson transmission line to generate a double flux quantum pulse at the transmission line output.