Page 58 - Phase-Locked Loops Design, Simulation, and Applications

MIXED-SIGNAL PLL ANALYSIS Ronald E. Best 42

■ For the passive lead-lag filter

(3.10)

■ For the active lead-lag filter

(3.11)

■ For the active PI filter

(3.12)

In circuit and control theory it is common practice to write the denominator of the transfer
function in the so-called normalized form 3

where ω is the natural frequency and ζ is the damping factor. The denominator of Eqs. (3.10)
n
to (3.12) will take this form if the following substitutions are made:

■ For the passive lead-lag filter:

(3.13)

■ For the active lead-lag filter:

(3.14)

■ For active PI filter:

(3.15)