Intel Pentium 4 Processor VR-Down Design Guidelines
Table Of Contents
- Output Requirements
- Voltage and Current REQUIRED
- Voltage Tolerance REQUIRED
- Load Line Definitions REQUIRED
- Processor Electrical And Thermal Current Support EXPECTED
- No-Load Operation EXPECTED
- Turn-on Response Time PROPOSED
- Processor Power Sequencing REQUIRED
- Overshoot at Turn-On or Turn-Off REQUIRED
- Converter Stability REQUIRED
- Thermal Monitoring PROPOSED
- Input Voltage and Current
- Control Inputs REQUIRED
- Power Good Output (PWRGD) PROPOSED
- Efficiency PROPOSED
- Fault Protection
Intel
®
Pentium
®
4 Processor VR-Down Design Guidelines
4
Applications and Terminology
This document defines DC-to-DC converters to meet the power requirements of computer systems
using Intel microprocessors. Requirements will vary according to the needs of different computer
systems and processors that a specific voltage regulator (VR) is expected to support. The “VR”
designation in this document refers to an embedded voltage regulator on a system board. Please refer
to the VRM 9.1 Design Guidelines for Voltage Regulator Module design guidelines. The major
differences between this document and the VRM 9.1 guidelines are:
This document defines solutions for systems with a single processor; it does not include current-
sharing requirements, which are applicable to powering multiple processors.
Voltages are specified at the processor socket instead of the VRM connector.
This document is specifically intended to meet the needs of systems based on the Intel
®
Pentium
®
4
processor in the 423-pin package, Intel Pentium 4 processor in the 478-pin package, and Pentium 4
processor with 512-KB L2 cache on 0.13 micron process. The specifications in the respective data
sheet always take precedence over the data provided in this document, which are guidelines to meet
processor requirements.
Each guideline is placed into one of three categories. The category immediately follows the section
heading and is one of the following:
REQUIRED: An essential part of the design—necessary to meet processor voltage and current
specifications and follow processor layout guidelines.
EXPECTED: Part of Intel’s processor power definitions: necessary for consistency among the
designs of many systems and power devices. May be specified or expanded by
system OEMs.
PROPOSED: Normally met by this type of DC-to-DC converter and, therefore, included as a
design target. May be specified or expanded by system OEMs.