We describe the design of an oversampling single-flux-counting analog-to-digital converter with the estimated bandwidth of a few tens MHz, based on Rapid Single-Flux-Quantum (RSFQ) devices. It consists of an input analog circuit, highspeed quantizer with an original analog/digital negative feedback loop, decimation (comb) Alter, and supporting subsysems including clock distribution circuits, quantization signal conditioner, and output drivers. We have applied a new approach, the 'symmetrizing' negative feedback, to free the quantizer from the intrinsic hysteresis without dynamic range sacriAce. The 16-bit version of the system comprises about 1,500 Josephson junctions and consumes 1.2 mW of dc power, when implemented using Nb-trilayer technology with 1 -kA/cm2, 3.5 -pm Josephson junctions.All subsystems of the converter have been successfully tested and testing of the system as a whole is in progress.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.