2-2
Intel
®
Pentium
®
III Processor with 512KB L2 Cache Dual Processor Platform Design Guide
Additional guidelines on board stack-up, placement, and layout include the following.
•
The board impedance (Z) should be between 55
Ω
and 75
Ω
(65
Ω
± 15% is recommended).
•
The dielectric process variation in the PCB fabrication should be minimized.
•
The ground plane should not be split on the ground plane layer.
•
Keep vias for decoupling capacitors as close to the capacitor pads as possible.
2.2
Socket 370 Component Keepout
Figure 2-2. Socket 370 Component Keepout
PGA 370 & PGA370S
All dimensions are minimum unless otherwise specified
No components
0 . 122" Max. Height Off MB
EMI Pads
0 . 060" Max. Height Off MB
0 . 127" Max. Height Off MB
1 . 022" Max. Height Off MB
1 . 38
2 . 528 . 005
REF .
PGA370
DESIGN
SPEC.
1 . 44
1 . 44
1 . 54
1 . 83
4X . 400
4X . 450
4X . 175
4X . 258
. 210
. 672
+
-
1 . 570
1 . 570
1.315
NOM
1.315
NOM
1 . 68
. 672
. 290
