29.3 A 48GHz 5.6mW Gate-Level-Pipelined Multiplier Using Single-Flux Quantum Logic

A multiplier based on superconductor single-flux-quantum (SFQ) logic is demonstrated up to 48GHz with the measured power consumption of 5.6 mW. The multiplier performs $8 \times 8 -$ bit signed multiplication every clock cycle. The design is based on a bit-parallel, gate-level-pipelined structure that exploits ultimately high-throughput performance of SFQ logic. The test chip fabricated using a $1.0- \mu \mathrm {m}$, 9-layer process consists of 20,251 Nb/AlOx/Nb Josephson junctions (JJs). The correctness of operation is verified by on-chip high-speed testing.