Voltage Regulator-Down (VRD) 10.1 Design Guide

Introduction
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Design Guide 9
1 Introduction
1.1 Applications
This document defines the power delivery feature set necessary to support Intel processors’ Vcc
power delivery requirements for desktop computer systems using the LGA775 socket. This
includes design recommendations for DC to DC regulators, which convert the input supply
voltage to a processor consumable Vcc voltage along with specific feature set implementation
such as thermal monitoring and dynamic voltage identification.
Hardware solutions for the Vcc regulator are dependent upon the processors to be supported by a
specific motherboard. At this time, two different VRD hardware configurations have been defined
for LGA775 processors. The Vcc regulator design on a specific board must meet the
specifications of all processors supported by that board. The voltage regulator configuration for a
given processor is defined in that processor’s datasheet.
The voltage regulator-down (VRD) designation of this document refers to a regulator with all
components mounted directly on the motherboard for intent of supporting a single processor. For
the corresponding documentation detailing voltage regulator modules (VRM) or a multiple-
processor VRD, please refer to the VRM 10 and EVRD 10 design guidelines document.
1.2 Terminology
Table 1-1. Feature Support Terminology
Categories Description
REQUIRED An essential feature of the design that must be supported to ensure correct
processor and VRD functionality.
EXPECTED A feature to ensure correct VRD and processor functionality that can be
supported using an alternate solution. The feature is necessary for consistency
among system and power designs and is traditionally modified only for custom
configurations. The feature may be modified or expanded by system OEMs if the
intended functionality is fully supported.
PROPOSED A feature that adds optional functionality to the VRD and, therefore, is included
as a design target. May be specified or expanded by system OEMs.