US Patent 7554369 Digital programmable frequency divider

A digital programmable frequency divider is constructed of Rapid Single Flux Quantum (RSFQ) logic elements. The logic elements may include an RSFQ non-destructive readout cell (NDRO), RSFQ D flip-flop and an RSFQ T flip-flop. A digital word comprising N bits is used to control the amount of frequency division and the frequency divider selectively imparts a respective frequency division for any of 2N states that can be represented by the digital word. The RSFQ logic elements utilize Josephson junctions which operate in superconducting temperature domains.