Stability investigation in RSFQ NDRO cell

There are several limitations on RSFQ circuit parameters determining their margins in critical conditions. We thoroughly investigated the sequential operation of the basic RSFQ circuits and study the corresponding behavior by comparing the measurable variables such as current response while modifying the eligible circuit's parameters. We introduce some figures of merit such as current level stability, current fluctuation damping after each pulse and circuit sensitivity, leading to obtain optimized parameters. A NDRO, cell based on T Flip-Flop (TFF), is particularly selected to verify the procedure. The optimized parameters are achieved by software simulation, considering the figures of merit. We also calculated the critical margins for main parameters in which the circuit is still remain stable.