hello,
we use a crstal oscillator (25MHz) as the input , and wish to get the following output clocks:
output 0 : 250MHz, LVDS
output 1 : 250MHz, LVDS
output 2 : 250MHz, LVDS
output 3 : 250MHz, LVDS
output 4 : 25MHz, LVDS
Are the registers datas right?
reg0:eb840320
reg1:eb840321
reg2:eb840302
reg3:eb840303
reg4: eb1e0314
reg5: 10000be5
reg6:84be03e6
reg7:bd907c27
Hi,
your configuration is fine BUT your loop filter is NOT SUFFICIENT. You seem to have a BW of 1.4M (too high) and insufficent phase margin of 25 only.
Please adjust loop filter components to:C1=21.5p
R2=4k
C2=473.5pF
R3=5k
C3=19.5pF
CP charge pump current = 600uA
This should get you PM=54, LBW=320k, gamma=0.93
Also, set the smart mux to AUX input only, since you only use XTAL, and disable PRI and SEC input..
Furthermore, unless you want to us the AUX output at 125MHz, you should disable this output for lowest noise and power consumption.