Kyushu University, Fukuoka, Japan 1 2 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 × 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-μm, 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. The SFQ logic [1] is a superconductor ultrafast digital circuit technology based on magnetic flux quantization and quantum interference in superconductor rings containing JJs. Binary information is represented by absence or presence of an SFQ in a superconductor ring, and JJs are used as switching elements. An impulse-shaped voltage is generated only when an SFQ travels across a JJ, which
Ikki Nagaoka1, Masamitsu Tanaka1, Koji Inoue2, Akira Fujimaki1
Nagoya University, Nagoya, Japan