SI5325C-C-GM Datasheet, PDF (117/178 Pages) Silicon Laboratories – ANY-FREQUENCY PRECISION CLOCKS

Si53xx-RM
High Reference Frequency
When selecting a reference frequency, with all other things being equal, the higher the reference frequency, the
lower the output jitter. Figures 65 and 66 compare the results with a 114.285 MHz crystal versus a 40 MHz crystal.
For a discussion of the available reference frequencies, see section " Resonator/External Clock Selection" on page
108.
Figure 65. 622.08 MHz Output with a 114.285 MHz Crystal
Jitter Band
Jitter, RMS
SONET_OC48, 12 kHz to 20 MHz
242 fs
SONET_OC192_A, 20 kHz to 80 MHz
269 fs
SONET_OC192_B, 4 to 80 MHz
166 fs
SONET_OC192_C, 50 kHz to 80 MHz
265 fs
Brick Wall_800 Hz to 80 MHz
270 fs
*Note: Jitter integration bands include low-pass (–20 dB/Dec) and hi-pass
(–60 dB/Dec) roll-offs per Telcordia GR-253-CORE.
Rev. 1.2
117