Intel 855Gme Chipset And Decoupling Guidelines; Gmch Vccsm Decoupling; Gmch Decoupling Recommendations - Intel 855GME Design Manual

®
Intel 855GME Chipset and Intel
4.8.1

Intel 855GME Chipset and Decoupling Guidelines

Decoupling in
board design.
Table 24. GMCH Decoupling Recommendations
Pin Name
VCC
VTTLF
VTTHF
VCCHL
VCCSM
VCCDVO
VCCDLVDS
VCCTXLVDS
VCCGPIO
SMVREF
4.8.1.1

GMCH VCCSM Decoupling

For the VCCSM pins of the GMCH, a minimum of eleven 0603 form factor, 0.1 µF, high-
frequency capacitors is required and must be placed within 150 mils of the GMCH package. The
capacitors shall be evenly distributed along the GMCH DDR system memory interface and placed
perpendicular to the GMCH with the power (2.5 V) side of the capacitors facing the GMCH.
•
Every GMCH ground and VCCSM power ball in the system memory interface shall have its
own via.
•
Each capacitor shall also have its own 2.5 V via within 25 mils of the capacitor pad for
connecting to a 2.5 V copper flood. The traces from the capacitors shall also be wide and
connect to the outer row of balls on the GMCH.
•
The ground end of each capacitor must connect to the ground flood and to the ground plane
through a via. Each via shall be as close to the associated capacitor pad as possible, within
25 mils and with as thick a trace as possible.
•
The system memory interface also requires low frequency decoupling. Place two 150 µF
electrolytic capacitors between the GMCH and the first DIMM connector.
108
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6300ESB ICH Embedded Platform Design Guide
Table 24 is based on the voltage regulator solution used on the customer reference
Configuration F
0.1 µF
Connect to
10 µF
VCC1_35S
150 µF
0.1 µF
Connect to VCCP 10 µF
150 µF
Connect to caps
0.1 µF
directly
0.1 µF
Connect to
VCC1_35S
10 µF
0.1 µF
Connect to
VCCSus2_5
150 µF
0.1 µF
Connect to
10 µF
VCC1_5S
150 µF
0.1 µF
Connect to
22 µF
VCC1_5S
47 µF
0.1 µF
Connect to
22 µF
VCCSus2_5
47 µF
0.1 µF
Connect to
Vcc3_3S
10 µF
0.1 µF
Qty TYPE
4 XR7, 0603, 16 V, 10%
1 XR5, 1206, 6.3 V, 20%
2 SPC, E, 6.3 V, 20%
2 XR7, 0603, 16 V, 10%
1 XR5, 1206, 6.3 V, 20%
1 SPC, E, 6.3 V, 20%
5 XR7, 0603, 16 V, 10%
2 XR7, 0603, 16 V, 10%
1 XR5, 1206, 6.3 V, 20%
11 XR7, 0603, 16 V, 10%
2 TANT, D, 10 V, 20%
2 XR7, 0603, 16 V, 10%
1 XR5, 1206, 6.3 V, 20%
1 SPC, E, 6.3 V, 20%
1 XR7, 0603, 16 V, 10%
1 TANT, B, 10 V, 20%
1 TANT, D, 10 V, 20%
3 XR7, 0603, 16 V, 10%
1 TANT, B, 10 V, 20%
1 TANT, D, 10 V, 20%
1 XR7, 0603, 16 V, 10%
1 XR5, 1206, 6.3 V, 20%
1 XR7, 0603, 16 V, 10%
Notes
1 X 0.1 µF within 200 mils
3 X 0.1 µF on bottom side
2 X 0.1 µF on bottom side
1 X 0.1 µF within 200 mils
1 X 0.1 µF on bottom side
Refer to Section 4.8.1.1
for more information.
1 X 0.1 µF within 200 mils
1 X 0.1 µF on bottom side
1 X 0.1 µF within 200 mils
1 X 0.1 µF within 200 mils
2 X 0.1 µF on bottom side
1 X 0.1 µF on bottom side