Voltage Regulator-Down (VRD) 10.0 Design Guide Addendum

VRD Design Guide Addendum

2 Processor Voltage Requirements

2.1 Voltage and Current (REQUIRED)

A six-bit VID code supplied by the processor to the VRD determines a reference output voltage,

as described in Section 3.2. The load lines in Section 2.2 show the relationship between Vcc and

Icc for the processor, and the tolerances between Vcc-minimum and Vcc-maximum.

Intel performs exhaustive testing against multiple software applications and software test vectors

to identify valid processor Vcc operating ranges. Failure to satisfy the load line, load line

tolerance band, and overshoot specifications (section 2.2, 2.3 and 2.8) may cause data corruption,

intermittent system lockup and lead to premature processor failure. In addition this could void the

Pentium 4 processor Extreme Edition supporting Hyper-Threading Technology in socket 478

processor warranty.

2.2 Load Line Definitions (REQUIRED)

The following load lines contain DC and transient-droop data as well as maximum and minimum

voltage levels. The voltages are measured at the processor-socket Vcc and Vss pins between the

voltage regulator and the processor cavity. For standard layouts these measurements are taken at

Vcc pin AC14 and Vss pin AC15. In some instances these two pins will not be located between

the voltage regulator and the processor cavity. In these cases, select pins that are centered in the

pin field between the cavity and the voltage regulator. It is recommended to place test points to

these pins on the bottom side of the motherboard to enable load line tuning and validation.

Table 1: Intel

Pentium

4 processor Extreme Edition Supporting Hyper-Threading

Technology Power Delivery Specifications

Iccmax VR TDC Dynamic Icc Socket Load

Line

VRD Tolerance

Band

Max VID

91A 80A 70A 1.50mOhms +/- 19mV 1.600

NOTE:

1. Maximum projected Pentium 4 processor Edition supporting Hyper-Threading Technology VID

The following figures and tables show load-line voltage offsets and current levels based on the

VID settings specified in Table 6. The following equations for the load lines are valid for the

range of load current from 0 A to 91 A.

Intel

Pentium

4 processor Extreme Edition Supporting Hyper-Threading

Technology Load Line Equations

MAX

load line: Vcc = VID – (1.50 mOhms * Icc)

TYP

load line: Vcc = VID – 0.019 V – (1.50 mOhms * Icc)

MIN

load line: Vcc = VID – 0.038 V - (1.50 mOhms * Icc)