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ADF4356

Question asked by hpkamen on Mar 8, 2017

Dear  Sir/Madam,

 

When I use ADF4356 phase-locked loop, I found strong spurious at frequency of the PFD harmonic , up to -75dBc, which can be seen as a Integer border stray, but the spurious is not exact at  the center frequency, but stay 15MHZ away from the center frequency, loop bandwidth is 40KHz, wha is the reason?
For example:
Phase-frequency is 50M, the output frequency is 5015M, and we could observe spurs between 5000M and 5030M , up to -75dBc, while the spurs on the output signal is also strong, up to about -82dBc, how to solve it?

Thanks.

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