INVESTIGATION OF THE SIGNAL RESOLUTION OF A HIGH-T-C BALANCED COMPARATOR

The use of high-T-c Josephson junctions far digital applications requi res a careful study of the influence of thermal noise on circuit perfo rmance. We investigated a balanced current comparator, which contains a basic component of all RSFQ circuits: two overdamped Josephson junct ions connected in series. The dependence of the dc-voltage across the Josephson junctions on signal current was measured to determine the th reshold uncertainty of switching of the comparator The experimental da ta obtained at different sampling pulse frequencies, in a temperature range from 10 to 50K were compared with a theoretical model, taking in to account the influence of thermal noise as well as of sampling pulse frequency.