Explain the concept of clock jitter in digital systems and its impact on signal integrity, timing analysis, and system performance.

Clock jitter refers to the deviation or variability in the timing of a clock signal from its ideal periodic waveform. It can introduce uncertainty and timing errors in digital circuits, affecting data sampling, signal integrity, and overall system performance. Techniques like jitter analysis, clock buffering, and jitter reduction PLLs are used to mitigate its effects.