mc9s12ne64 Freescale Semiconductor, Inc, mc9s12ne64 Datasheet - Page 519

• Manufacturer Part Number: mc9s12ne64
• Description: Hcs12 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

The following procedure can be used to calculate the resistance and capacitance values using typical values
for K
The grey boxes show the calculation for f
for f
The VCO Gain at the desired VCO frequency is approximated by:
The phase detector relationship is given by:
i
The loop bandwidth f
typical values are 50. ζ = 0.9 ensures a good transient response.
Freescale Semiconductor
ch
is the current in tracking mode.
OSC
1
, f
1
= 4 MHz and a 25 MHz bus clock.
and i
ch
from Table A-13.
f
osc
K
V
C
f
should be chosen to fulfill the Gardner’s stability criteria by at least a factor of 10,
C
=
K
<
refdv+1
K
Φ
------------------------------------------
π
1
Figure 18-22. Basic PLL Functional Diagram
⋅
=
1
⋅
⎛
⎝
2 ζ f
e
ζ
–
(
---------------------- -
⋅ ⋅
+
f
K
i
1
ch
MC9S12NE64 Data Sheet, Rev. 1.1
1
f
–
ref
⋅
V
1
f
VCO
1V
vco
⋅
ref
DDPLL
+
K
=
)
V
ζ
= 50 MHz and f
2
–
⎞
⎠
100
∆
f
----- -
10
cmp
1
C
C
⋅
p
→
Loop Divider
e
s
Detector
(
----------------------
= 316.7Hz/Ω
Phase
60 50
synr+1
f
–
f
K
C
C
100
Φ
ref
–
1
<
R
< 25kHz
= 1 MHz. E.g., these frequencies are used
Reset, Oscillator, and PLL Electrical Characteristics
------------ - ζ
4 10
= -90.48MHz/V
f
)
ref
⋅
;
(
XFC Pin
=
0.9
1
2
VCO
)
K
V
f
vco
519