A 10-Gb/s 275-fsec Jitter Cryo-CMOS Charge-Sampling CDR for Quantum Computing Application

This letter presents the first clock and data recovery (CDR) system operating at 4.2 K designed for quantum computing (QC) applications. By considering the benefits and challenges of cryogenic operation, a dedicated analog CDR structure is employed so as to maintain high performance at 300 and 4.2 K. The CDR incorporates a new complementary charge-sampling phase detector (PD) that achieves low power and low jitter. Fabricated in 40-nm CMOS, the proposed CDR operates at 10 Gb/s, achieving a recovered clock jitter of 260 fs and a jitter tolerance of $2 {\mathrm{ UI}}_{\mathrm{ PP}}$ at a 5-MHz jitter frequency while consuming 4.7 mW at room temperature (RT). At 4.2 K, the power consumption reduces to 3.1 mW with a recovered clock jitter of 275 fs and a jitter tolerance of $0.85 {\mathrm{ UI}}_{\mathrm{ PP}}$ at a 5-MHz jitter frequency, demonstrating its functionality for a high-speed cryogenic wireline link.