hi all
the amount of the reference spur ,in the 3rd order PLL is approxiantely
20log [square(2)*Icp*R*Q*Kvco/2*Fref]-20log[Fref/Fp1]
R is the res of loop fiter ,Kvco VCO gain,Fref reference frequency for PDF ,Fp1 loop fiter pole,Q is the phase offset
can anyone explain why ?
the equation refers to the paper of design of high-perfermance CMOS chargepumop in phase-locked loops
thanks in advance