Page 125 - Phase-Locked Loops Design, Simulation, and Applications
P. 125
capacitor needs twice as much time to charge. Therefore, the loop filter acts like a simple RC
filter whose time constant is not τ + τ but 2(τ + τ ). The equivalent model of Fig. 3.19 can
1
1
2
2
now be used to compute the signal u across capacitor C . Since the VCO of the PLL was
f 1
assumed to operate at its center frequency ω at the start of the pull-in process, the initial
0
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