Datasheet

18 Intel
®
Pentium
®
4 Processor on 0.13 Micron Process Datasheet
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 on the Pentium 4
processor on 0.13 micron process. Since these PLLs are analog, 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 V
CC
. A typical filter topology is shown in Figure 2-2.
The AC low-pass requirements, with input at V
CC
and output measured across the capacitor
(C
A
or C
IO
in Figure 2-2), 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
Refer to the appropriate platform design guide for recommendations on implementing the filter.
Table 2-2. Voltage Identification Definition
Processor Pins
V
CC_MAX
VID4 VID3 VID2 VID1 VID0
11111VRM output off
111101.100
111011.125
111001.150
110111.175
110101.200
110011.225
110001.250
101111.275
101101.300
101011.325
101001.350
100111.375
100101.400
100011.425
100001.450
011111.475
011101.500
011011.525
011001.550
010111.575
010101.600