Single Flux, Quantum B Flip-Flop and Its Possible Applications

single-flux-quantum (RSFQ) digital cells, based on a single B flip-flop template. The template can be considered as an SFQ flip-flop with up to 4 inputs and 6 outputs. Each input SFQ pulse can change the flip-flop’s internal state. Each output presents (in the form of SFQ pulses a specific logic function of the initial state of the cell and input signals. Simple connection of various inputs and/ or outputs, combined with shortening or opening of certain branches of the template allows one to implement a variety of RSFQ cells with wide margins. Of these various RSFQ cells, we have designed and successfully tested the T1 cell (asynchronous toggle flip-flop with synchronous destructive readout), single-bit full adder, and single-bit stage of an up-down counter. Experimentally measured margins for dc power supply voltage for these circuits were ±24%, ±24%, and ± 17%, respectively.