This tool converts from crystal oscillator stability in terms of parts per million (ppm) to the equivalent frequency variation (Hz/kHz/MHz/GHz)
Formula
The frequency variation df on either side of the center frequency F is given by
df = F*ppm*10-6
The maximum and minimum frequency are given by
Fmax = F + df
Fmin = F – df
Example
The 32 MHz oscillator has a frequency stability of +/- 25 PPM.
The oscillator can be used as a reference clock with a phase locked loop to generate a frequency of 1 GHz.
Enter these numbers into the calculator above to calculate a frequency variation of +/- 25 kHz. The minimum and maximum frequencies generated are 999.975 MHz and 1000.025 MHz, respectively.