AnsweredAssumed Answered

ADF4108 Not Locking

Question asked by JTORRES on Feb 6, 2018
Latest reply on Feb 22, 2018 by aandrews

Hi Everyone,


I'm testing my ADF4108 based design, I am using a Synergy Microwave VCO that works up to 8GHz and I want to generate signals in the frequency range near 7400 MHz.


I am using a 20 MHz TCXO as a REF_IN clock and a passive filter loop designed with ADISimPLL, when y set the R register the output signal goes to the higher limit (Vcp=5V) and when I introduce AB register, no matter the A and B values I set, the output frequency goes to 7.08 GHz. My configuration procedure is Initialization Latch Method


My configuration registers are:

Init: 0x800013

Function: 0x800012

R: 0x120280 (R=160)

AB (For 7412MHz):  0x073D01 



Steps 125kHz (20MHZ /160)

P= 32/33





I hope anybody could help me with this.


Best Regards,