Demonstration and Comparison of On-Chip High-Frequency Test Methods for RSFQ Circuits

Abstract

On-chip high-frequency test for Rapid Single Flux Quantum (RSFQ) circuits without external high-frequency equipment is very attractive and promising. The test method based on Shift Register (SR) is widely used for long time. Recently, we have proposed two test methods based on Pseudo Random Binary Sequence (PRBS) generator. In this paper, a Full Adder (FA) is taken as an example of circuit under test and the design methodology of the above approaches is presented. For FA with the traditional and two proposed approaches, the high-frequency test circuits are fabricated and tested. We demonstrate the successful measurement of the three circuits with the maximum operating frequency of the full adder at 23.3 GHz, 26.2 GHz and 27.4 GHz respectively. Based on the experimental results, the clock frequency measurement in the proposed two PRBS based test systems is more accurate and time-saving, which is advantageous for high-frequency RSFQ circuits measurement.