Intel Xeon User Manual

Platform Power Delivery Guidelines
162 Design Guide
12.1.7 3.3 VSB
The 3.3 VSB power plane is the output of a 5 VSB-to-3.3 VSB voltage regulator. The power plane
is used solely for the resume I/O features of the ICH3-S. This segment is given only about 64 mA.
This regulator is required in all designs.
12.1.8 1.8 VSB
As stated before, the 1.8 VSB provides power to the resume logic within the ICH3-S. This logic
uses about 14.01 mA. This regulator is required in all designs.
12.1.9 Power Summary
The following table summarizes the platform power.
12.2 Processor Power Distribution Guidelines
12.2.1 Processor Power Requirements
This section describes the requirements for supplying power to a Intel Xeon processor. For detailed
electrical specifications, refer to the Intel
®
Xeon™ Processor with 512 KB L2 Cache at 1.80 GHz,
2 GHz, and 2.20 GHz Datasheet. The processor will typically operate between VCC_MID and
VCC_MAX. The processor allows the use of Auto HALT, Stop-Grant, Sleep, and Deep Sleep
states to reduce power consumption by stopping the clock to specific internal sections of the
processor and the BCLK depending on each particular state. This can create load-change transients
as high as 450 amps per microsecond on VCC_CPU at the socket pins. Note that the processor can
also cause load changes of this magnitude while executing regular code. In this document, a load-
change transient is a change from one current requirement (averaged over many clocks) to another.
In the future, the processor may require higher currents and different voltages.
12.2.1.1 Multiple Voltages
“VCC_CPU” in this section refers to the processor core VCC, cache supply voltage, and Assisted
Gunning Transceiver Logic + (AGTL+) supply voltage. In the processor, the core and cache are on
the same silicon and are powered from the same power plane–unlike Pentium II Xeon and
Pentium
III Xeon processors, which required different power planes.
Table 12-1. Power Summary
Power Rail Source Destination Max Current
CPU VRM 9.1 / VRD 2 CPUs, MCH, Intel
®
ICH3-S 126 A
2.5 V 5 V switching regulator MCH DDR 26 A
1.25 V 5 V to 2.5 V switching regulator MCH DDR 12.5 A
1.8 V 5 V switching regulator P64H2, ICH3-S 13.86 A
1.2 V 1.8 V switching regulator MCH 3.1 A
5 VSB Power Supply 3.3 VSB, 1.8 VSB 78 mA
3.3 VSB 5 VSB voltage regulator ICH3-S 64 mA
1.8 VSB 5 VSB voltage regulator ICH3-S 14.01 mA

Intel Xeon Specifications

General

Brand	Intel
Model	Xeon
Category	Processor
Language	English