Intel 855GME Design Manual page 98

®
Intel 855GME Chipset and Intel
compared to the 17.1 pH (600 pH/35) inductance of the thirty-five 0805 decoupling capacitors.
When alternative layout solutions are used, they shall be implemented with a level of robustness
greater than or equal to that in the previous example. In terms of robustness, this refers to creating
a low resistance and inductance connection between the bulk and mid-frequency capacitors and the
processor pins.
For options 1 to 3 in
through Figure 47
implementations of option 4 compared to options 1 to 3 is the use of 0612 reverse geometry
capacitors. To be effective, these 0612 capacitors need to occupy the space within the Intel Pentium
M/Celeron M processor socket cavity shadow on the secondary side for both the north and south
sides of the pin-map as well as outside the socket shadow along the 'north power corridor' pins.
Intel recommends the adoption of option 4 for the V
used, the arrangement of the V
field is recommended to be refined based on recommendations and layout example described
above.
Figure 44. V
CC-CORE
Option 4 (Primary and Secondary Side Layers)
Primary Side Primary Side
1.8v 1.8v
VCCA VCCA
To Intel® To Odem
855GME
1.8v
Chipset
98
®
6300ESB ICH Embedded Platform Design Guide
Table 21, the layout concepts described above and depicted in
are also similar in many respects. The main difference between the layout
CC-CORE
Power Delivery and Decoupling Example –
Sense Resistors Sense Resistors
VR Feed VR Feed
2 2
V V CC_COR
CC_COR
VCCP VCCP
L1 PS
L1 L1
L2 GND
L2 L2
L3 Sig
L3 L3
L4 GND
L4 L4
L5 L5 L5 PWR
L6 L6
L6 Sig
L7 L7
L7 GND
L8 L8
L8 SS
decoupling. When option 1, 2, or 3 is
CC-CORE
/GND vias in the Intel Pentium M/Celeron M processor pin
Secondary Side Secondary Side
- -
+ +
3 3
1 1
+ +
8x10uFx0805
µ
8x10 Fx0805
VCCP
To Intel®
VCCP
855GME
To
Chipset
Odem
+ + +
Figure 42
4x220uF SP Cap
µ
4x220 F SP
- -
- -
- -
+ +
+ +
+ +
3 3
+ +
+ +
+ +
V CC_COR V
CC_COR
E
E
µ
9x10 Fx805
9x10uFx0805
VCCP VCCP
VCCP VCCP
To ITP To ITP
µ
9x10uFx0805
9x10 Fx0805
Cross Cross
Section Section
View View
+ + + +
- - -