Pipelined DC-powered SFQ RAM
We present the design and test results of components for a superconductor Cryogenic Random Access Memory (CRAM). The 16-Kb RAM design consists of four 4-Kb sub-arrays (blocks) with a 400 ps access time (latency) and a 100 ps cycle time (throughput). Each 4-Kb RAM block comprises a row-accessed 32/spl times/128 memory cell array, bipolar line drivers, row decoders, and column sense circuits. The implementation of specially designed distributed Josephson junctions in the sensing circuits reduces the overall size of the blocks and allows the use of smaller dc control currents.