Ultra-low-power RSFQ devices and digital autocorrelation of broadband signals

Wanju Cho, Gunhwi Moon

The development technique of digital logic using CMOS device is close reached several limitations These make technical needs that are ultra high speed superconductive systems based on CMOS silicon digital computing technique. Comparing digital logic based on silicon CMOS, the computing technique based on ultra high speed superconductive systems has many advantages which are ultra low power consumption, ultra high operation speed. etc. It is estimated that features like these increasingly improve the possibility of ultra low power and ultra superconductive systems. In this paper digital logics of current CMOS technique and RSFQ superconductive technique are compared with and analyzed.

T. Van Duzer, L Zheng, Xiangchao Meng +6 more

Yoshinobu Tarutani, Kazuo Saitoh, Kazumasa Takagi

Alexander V. Rylyakov

We present a new design of a Rapid Single-Flux-Quantum (RSFQ) all-digital one-bit autocorrelator for submillimeter spectrometry applications, featuring 4 GHz input signal bandwidth, double oversampling quantizer, and 16 Mbps-per-channel output rate. The delay line of the autocorrelator is based on a circular shift register with XOR gates performing multiplication of the delayed and undelayed single-bit signals at every stage. The multiplication results are accumulated by room-temperature electronics after being prescaled in on-chip binary counters consisting of 10 T flip-flops per stage. We report results of experimental testing of a 16-stage autocorrelator delay line with multiplication and for a linear array of 8 low-power T flip-flop binary counters, all fabricated in HYPRES' standard 3.5 /spl mu/m 1000 A/cm/sup 2/ Nb-trilayer process. We also discuss physical and technical limits of the minimal power dissipation in RSFQ circuits.

Alexander V. Rylyakov, D.F. Schneider, Yu. A. Polyakov

We present the results of low- and high-speed testing of a fully integrated all-digital one-bit RSFQ autocorrelator for short-millimeter and submillimeter wave spectrometry applications. The 16-channel device, complete with a 16/spl times/9 array of binary counters, on-chip double-oversampling quantizer and on-chip clock was operational at clock speeds of up to 11 GHz. The total number of Josephson junctions in the design was 1672, while the estimated total power dissipation was less than 0.1 mW. For high-speed testing of the device we have developed a specialized 16-channel room-temperature interface capable of real-time data acquisition at a 16 Mbps-per-channel output rate. Extensive high-speed on-chip testing of the autocorrelator has also been performed, both in analog and digital modes, in the latter mode with an additional on-chip clock controller. All chips were fabricated in HYPRES' standard 3.5 /spl mu/m-10 /spl mu/A//spl mu/m/sup 2/ Nb-trilayer process. We also present a new concept of a 128-channel autocorrelator system built on 8 independent identical chips with approximately 2,500 Josephson junctions per chip, i.e. within the reach of the present-day fabrication technology.

Romain Collot, Pascal Febvre, Thierry Robert +3 more