Guide

Platform Design Checklist
R
266 Intel
®
852GM Chipset Platform Design Guide
14.8.15. ICH4-M Decoupling Recommendations
Pin Name Configuration Value Q Notes
9
VCC1.5 Connect to Vcc1_5 0.1 µF 2 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 22 µF and one 100 µF.
VCC3.3 Connect to Vcc3_3 0.1 µF 6 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
two 22 µF.
VCCSUS1.5 Connect to
V1_5ALWAYS
0.1 µF 2 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 10 µF.
VCCSUS3.3 Connect to
V3ALWAYS
0.1 µF 2 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 22 µF.
VCCLAN1.5 Connect to
VccSus1_5
0.1 µF 2 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 22 µF.
VCCLAN3.3 Connect to
VccSus3_3
0.1 µF
4.7 µF
2
1
Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 22 µF.
VCC5REF Connect to Vcc5
through 1K
Ω
0.1 µF
1 µF
1
1
Caps from VCC5REF to ground. Also connect
diode from VCC5REF to Vcc3_3.
VCC5REFSUS Connect to
V5ALWAYS through
1K
Ω
0.1 µF
1 µF
1
1
Caps from VCC5REFSUS to ground. Also
connect diode from VCC5REFSUS to
V3ALWAYS.
VCC_CPU_IO Connect to VCCP 0.1 µF
1 µF
1
1
VCCPLL Connect to Vcc1_5 0.1 µF
0.01 µF
1
1
VCCRTC Connect to VccRTC 0.1 µF 1
VCCHI Connect to Vcc1_5 0.1 µF 2 Low frequency decoupling is dependent on
layout and power supply design. CRB uses
one 22 µF.
NOTE: All decoupling guidelines are recommendations based on our reference board design. Customers will need
to take their layout and PCB board design into consideration when deciding on their overall decoupling
solution. Capacitors should be place less than 100 mils from the package.