Basics of Closed- and Open-Loop Fractional Frequency Synthesis - Pamarti | CICC 2020 | Educ. Session

ES2-2 Basics of Closed- and Open-Loop Fractional Frequency Synthesis Sudhakar Pamarti, University of California, Los Angeles Fractional frequency synthesis is employed in a wide variety of applications, and the circuits that realize fractional frequency synthesis come in several forms. This talk presents the basics of fractional frequency synthesis by roughly grouping them into closed loop approaches such as those based on phase locked loops, and open loop approaches such as those based on fractional dividers and digital-to-phase converters. The talk will describe how these systems work, focusing on commonalities such as the use of digital delta sigma modulators, and on unique differences. The talk will also explore metrics such as phase noise, jitter, and spurious tones in these systems using examples wherever appropriate.