Intel Xeon Processor and Intel E7500/E7501Chipset Compatible Platform Design Guide

Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide 203
Platform Power Delivery Guidelines
11.5 Intel
®
P64H2 Power Requirements
11.5.1 Intel
®
P64H2 Current Requirements
For more information, refer to the Intel
®
82870P2 PCI/PCI-X 64-bit Hub 2 (P64H2) Thermal Design Guide.
11.5.2 Intel
®
P64H2 Decoupling Requirements
The P64H2 is capable of generating large current swings when switching between logic high and
logic low. This condition could cause the component voltage rails to drop below specified limits.
To avoid this, ensure that the appropriate amount of bulk capacitance is added in parallel to the
voltage input pins. It is recommended that the developer use the amount of decoupling capacitors
specified in the table below to ensure the component maintains stable supply voltages. The
capacitors should be placed as close to the package as possible.
NOTES:
1. In the case of the 20 0.1 µF decoupling capacitors for the Vcc3.3 plane, it is recommended that at least five of
these capacitors be placed near the die on the back of the board between ground and the VCC-PCI vias, as
shown in Figure 11-28. This is not a strict requirement, but is recommended to reduce the power resonance
frequency at 66 Hz.
Table 11-9. Intel
®
P64H2 Max Sustained Currents
Voltage at PCI/PCI-X Interface Max Sustained Current
1.8 V at 33 MHz PCI (both segments) 1970 mA
1.8 V at 66 MHz PCI/PCI-X (both segments) 2170 mA
1.8 V at 100 MHz PCI-X (both segments) 2550 mA
1.8 V at 133 MHz PCI-X (both segments) 2660 mA
3.3 V at 33 MHz PCI 6 loads (both segments) 930 mA
3.3 V at 66 MHz PCI 2 loads (both segments) 690 mA
3.3 V at 66 MHz PCI-X 4 loads (both segments) 1300 mA
3.3 V at 100 MHz PCI-X 2 loads (both segments) 1050 mA
3.3 V at 133 MHz PCI-X 1 load (both segments) 770 mA
Table 11-10. Decoupling Capacitor Recommendations
Power Plane/Pins
Number of
High-Frequency
Decoupling
Capacitors
High-Frequency
Capacitor
Values
Number of Bulk
Decoupling
Capacitors
Bulk
Capacitor Values
1.8 V Core (VCC) 8 0.1 µF 2 4 µF (near Intel
®
P64H2)
1.8 V HI 2.0
(VCC1_8)
2 1.0 µF 1 100 µF (near regulator)
3.3 V PCI/PCI-X
(VCC3_3)
20
1
0.1 µF 2 4 µF (near P64H2)
6 1.0 µF 1 100 µF (near regulator)