Intel 4 620 JM80547PG0722MM Data Sheet
Product codes
JM80547PG0722MM
Datasheet
19
Electrical Specifications
2.4.1
Phase Lock Loop (PLL) Power and Filter
V
CCA
and V
CCIOPLL
are power sources required by the PLL clock generators for the Pentium 4
processor. Since these PLLs are analog, they require low noise power supplies for minimum jitter.
Jitter is detrimental to the system: it degrades external I/O timings as well as internal core timings
(i.e., maximum frequency). To prevent this degradation, these supplies must be low pass filtered
from V
Jitter is detrimental to the system: it degrades external I/O timings as well as internal core timings
(i.e., maximum frequency). To prevent this degradation, these supplies must be low pass filtered
from V
TT
.
The AC low-pass requirements, with input at V
TT
are as follows:
•
< 0.2 dB gain in pass band
•
< 0.5 dB attenuation in pass band < 1 Hz
•
> 34 dB attenuation from 1 MHz to 66 MHz
•
> 28 dB attenuation from 66 MHz to core frequency
. Contact your Intel representative for further
details and documentation.
.
NOTES:
1. Diagram not to scale.
2. No specification exists for frequencies beyond fcore (core frequency).
3. fpeak, if existent, should be less than 0.05 MHz.
2. No specification exists for frequencies beyond fcore (core frequency).
3. fpeak, if existent, should be less than 0.05 MHz.
Figure 2-1. Phase Lock Loop (PLL) Filter Requirements
0 dB
–28 dB
–34 dB
0.2 dB
–0.5 dB
1 MHz
66 MHz
fcore
fpeak
1 Hz
DC
Passband
High
Frequency
Band
Forbidden
Zone
Forbidden
Zone