How to select PFD Frequency for ADF4360-9?. i am using this for generating 20-100 MHz with divider output.
Can you explain what value i need to place there to cover over the my required frequency.
As this is an Integer N PLL, the maximum PFD should not be greater than the minimum channel spacing required, for best performance you should use as close to the maximum PFD frequency that this part is specified for, which is 8Mhz, I would suggest that you download our ADIsimPLL( if you havent already done so ) and input your required set-up, if you need additional help, you can send me your .pll file.
Thank you for information, i want to use this PLL for generating 1.5-30 MHz & 20-100 MHz.can you tell which is best way to approach to get good performance and also suggest if any issue in my selection. i used 10 MHz (0 dBm) signal for Reference frequncy? is it enough to operate ADF4360-9 for generating 1.5-30 & 20-100 MHz output
What channel spacing do you need ?
for the frquency band 20-100, i need 100 KHz step size
If your step is 100Khz, then you need to use a PFD of 100Khz, however please be aware that the VCO tuning range is limited to 1.2( see ADF4360-9 datasheet), our ADF4351 can cover down to 35Mhz, what is this application for?
what is the relation between PFD & stepsize, and Between PFD & Ref frequency
Refer to fig 1, the block diagram on page 1 of the ADF4360-9 datasheet,
The PFD frequency is = fvco / N counter value, if the o/p is taken from the RFoutA ( B), then the step size = PFD freq, if however you use the divide by A ( and divide by 2), then the step size is further divided by A ( and 2, if dvide by 2 enabled) .
The PFD = Ref freq / R Counter.
For the ADF4360-9, I see the phase detector frequency = 8 MHz max (data sheet page 3). But, on page 11 it says: The R counter output is used as the clock for the band select logic and should not exceed 1 MHz." Since R counter output = phase detector frequency, these two requirements contradict each other. Or, does the 1 MHz max refer to 8 MHz max divided by the band select clock divider = 8? I think I just answered my question but please confirm.
Correct.." the 1 MHz max refer to 8 MHz max divided by the band select clock divider = 8" .Regards Brigid.
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