Hello，
I connected LMX2492 to an external VCO, and loop filtering adopted the fourth-order passive form. The simulation control adopted the TiPLLatinum and TICS Pro provided by Ti, in which the phase margin was set at 49.7° and the loop bandwidth was 437KHz. However, the output frequency could not be locked all the time, may I ask what caused it?Another question is what is the role of Kpd regulation, is the larger the setting, the better its phase noise performance?When I set the Kpd at 3.1mA, the remote phase noise (5MHz) got worse.The above Settings Fpd=40MHz, R_divider=1,FVco=1.5GHz, Kpd=0.4mA, Kvco=36MHz/V
Looking forwards to your suggestions!
Best regards
Kailyn
