Self-Healing Phase-Locked Loops in Deep-Scaled CMOS Technologies

Researchers described automatic frequency calibration and amplitude control techniques that relied on a negative feedback loop with a large emphasis on digitally assisted calibration. The researchers presented a self-healing phase-locked loop (PLL) repair approach and described simulations conducted during the course of exploring the design issues. The self-healing technique focused on minimizing performance deviation from the target value by using automatic calibration circuits in comparison with the traditional design methodology that dealt with worst-case scenarios and tried to shift the overall distribution to the high-performance side. The automatic calibration techniques relied on one common design methodology, such as a negative feedback loop using an integrated sensor and a difference detector.