Intel G470 BX80623G470 Benutzerhandbuch
Produktcode
BX80623G470
16
Intel
®
Celeron
®
Processor on 0.13 Micron Process in the 478-Pin Package
Datasheet
Electrical Specifications
2.4.1
Phase Lock Loop (PLL) Power and Filter
VCCA and VCCIOPLL are power sources required by the PLL clock generators on the Celeron
processor on 0.13 micron process. Since these PLLs are analog in nature, they require quiet 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 VCC. A typical filter topology is shown in
processor on 0.13 micron process. Since these PLLs are analog in nature, they require quiet 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 VCC. A typical filter topology is shown in
.
The AC low-pass requirements, with input at VCC and output measured across the capacitor
(C
(C
A
or C
IO
), is 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
. For recommendations on implementing the filter,
Table 3. Voltage Identification Definition
Processor Pins
Vcc_max
VID4
VID3
VID2
VID1
VID0
1
1
1
1
1
VRM output off
1
1
1
1
0
1.100
1
1
1
0
1
1.125
1
1
1
0
0
1.150
1
1
0
1
1
1.175
1
1
0
1
0
1.200
1
1
0
0
1
1.225
1
1
0
0
0
1.250
1
0
1
1
1
1.275
1
0
1
1
0
1.300
1
0
1
0
1
1.325
1
0
1
0
0
1.350
1
0
0
1
1
1.375
1
0
0
1
0
1.400
1
0
0
0
1
1.425
1
0
0
0
0
1.450
0
1
1
1
1
1.475
0
1
1
1
0
1.500
0
1
1
0
1
1.525
0
1
1
0
0
1.550