It is obvious, that time-frequency duality indicates, that phase noise can be converted to rms jitter. Phase noise is usually measured in terms of dBc/Hz where the “c” indicates with respect to the power of the carrier. Once this measurement is done it is possible to convert the phase noise between frequency limits to rms jitter using the following formula: rms phase jitter ( in radians) = sqrt [ 2.0*10** (A/10)]. Here ** indicates exponentiation. A is the power in dBc over the band. This is simply the area under the phase noise curve.(If the jitter is to be used in terms of seconds, divide by 2*pi*fo, where fo is the oscillator center frequency). A number of good routines are available freely on the web to calculate the area under the noise power curve. (To read about the phase noise please visit http://www.signalpro.biz/register.html and select the oscillator noise paper…)This identity is embodied in the jitter calculator that can be accessed from the Signal Processing Group Inc website from the free items link.