Clock ( CLK ) Jitter and Phase Noise Conversion

Period Jitter Period jitter (JPER) is the time difference between a measured cycle period and the ideal cycle period. Due to its random nature, this jitter can be measured peak-to-peak or by Root of Mean Square (RMS). We begin by defining the clock rising-edge crossing point at the threshold VTH as TPER(n), where n is the time domain index, as shown in Figure 1. Mathematically, we can describe JPER as: