Appendix A Electrical Characteristics
MC9S12XDP512 Data Sheet, Rev. 2.11
948 Freescale Semiconductor

And finally the frequency relationship is defined as

With the above values the resistance can be calculated. The example is shown for a loop bandwidth

fC= 20 kHz:

The capacitance Cs can now be calculated as:

The capacitance Cp should be chosen in the range of:

A.5.3.2 Jitter Information
The basic functionality of the PLL is shown in Figure A-3. With each transition of the clock fcmp, the

deviation from the reference clock fref is measured and input voltage to the VCO is adjusted

accordingly.The adjustment is done continuously with no abrupt changes in the clock output frequency.

Noise, voltage, temperature and other factors cause slight variations in the control loop resulting in a clock

jitter. This jitter affects the real minimum and maximum clock periods as illustrated in Figure A-4.

Figure A-4. Jitter Definitions
fC
2ζfref
⋅⋅
πζ 1ζ2
++
⎝⎠
⎛⎞
-------------------------------------------1
10
----- fC
fref
410
-------------ζ0.9=();<<
fC < 100kHz
n
fVCO
fref
--------------- 2 synr 1+()== = 20
R
2πnf
C
⋅⋅⋅
KΦ
----------------------------- 2π20 20kHz⋅⋅ ⋅
539.1Hz()
------------------------------------------4.7k===
Cs
2ζ2
πfCR⋅⋅
---------------------- 0.516
fCR
---------------ζ0.9=();== = 5.5nF = ~ 4.7nF
Cs
20
------ Cp
Cs
10
------
≤≤ CP = 470pF
2 3 N-1 N1
0
tnom
tmax1
tmin1
tmaxN
tminN