Clock Accuracy / Jitter
Clock accuracy and jitter describe different aspects of timing: average frequency error and short-term variation in clock timing.
Accuracy indicates how closely the clock’s frequency follows its intended value, often using parts per million. Jitter describes variations in the timing of clock edges and may be expressed in units of time. These quantities should not be combined into one interchangeable rating.
Compare accuracy under equivalent temperature, ageing and operating conditions. Compare jitter only when the measurement type, bandwidth and reported basis are compatible; an RMS figure and a peak-to-peak figure are different. A clock can have good average frequency accuracy without establishing a particular jitter result. Neither number alone describes the complete analogue output performance of a digital audio system.