ScholarWorks@성균관대학교

초록

Reference-less clock and data recovery (CDR) operates without an external clock, improving system efficiency [1]-[7]. Specifically, oversampling and injection methods are widely used for superior noise immunity in high-speed operations. These methods have been applied to enhance frequency-locked loops (FLLs) or phase-locked loops (PLLs). In studies on FLL ([2], [3]), the oversampling method was applied by rotating the sampling clock for frequency offset correction. However, under high jitter conditions, these designs are vulnerable to dead zones near data edges, compromising frequency offset detection accuracy. In studies on PLL ([4], [5]), the Injection method was applied to enhance loop bandwidth. But this approach requires precise delay line calibration to manage mismatches between the main and injection paths, adding design complexity.