SimPLL doesn't take account into phase & BW info. of Op-Amp for active filter. ADF4159 EVB uses OP184 which is 4MHz BW. When we set around 1MHz loop-filter, it causes the peak amplitude discrepancy between simulation and measurement at 1MHz offset, and in addition, op-amp oscillates and VCO is modulated, like FM signal at certain Charge pump current condition.
Could you add an option on simPLL that takes care about op-amp parameters?
