Voltage Regulator-Down (VRD) 10.0

Introduction

VRD Design Guide 7

1 Introduction

This document defines the power delivery feature set necessary to support Intel processors’ Vcc

power delivery requirements for desktop computer systems using socket 478. This includes design

recommendations for DC-to-DC regulators which convert the 12 V supply to the 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 microprocessors to be supported

by a specific motherboard. At this time, four different VRD hardware configurations have been

defined for socket 478 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. In some instances, this data is not

published and the proper mapping of processor to VRD configuration can be found

Table 5 or from an authorized Intel representative.

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.

VRD 10 incorporates functional changes from previous VRD standards:

• Addition of Dynamic Voltage Identification (D-VID): Ability to change the Vcc reference by

request of the processor (Section 2.8)

• Simplified definition of power-good as a power-up indication (Section 6.1)

• VRD recognition of processor induced off states (Section 3.2)

• Thermal monitoring of the VRD (Section 6.2).

• V

Overshoot specification (Section 2.9)