Chapter 7 Power and Signal Distribution

7.3.2 LOW VOLTAGE PRODUCTION/DISTRIBUTION

Voltages less than 3.3 VDC including processor core (VCore) voltage are produced through regulator circuitry (Figure 7-4) on the system board.

Power Supply

+12.8 VDC

+5 AUX

+3.3 VDC

3.3

Auxiliary

Circuit

3.3 AUX

3.3 AUX

1.5 / 1.4

Regulator

Circuit

1.2

Auxiliary

Circuit

DDR

S3 PWR

Circuit

3.3 AUX [1]

DIMMs

1.2AUX Chipset

2.6VDC

+1.3 VDC

DDR DIMMs

+1.5 VDC

 

+1.4 VDC

Chipset

 

+12 VDC

 

+5 VDC

VID0

VID1

ProcessorVID2 VID3

VID4

Regulator

Circuit

PWM A

+12.8 VDC

PWM B

+12.8 VDC

PWM C

+12.8 VDC

Driver Circuit A

Driver Circuit B

Driver Circuit C

MOSFET

Finals

Processor

VCore

Figure 7-4.Low Voltage Supply and Distribution Diagram

The regulator produces the VCore (processor core) voltage according to the strapping of signals VID4..0 by the processor. The possible voltages available are listed as follows:

VID 4..0

VCore

00000

1.850

00001

1.825

00010

1.800

00011

1.775

00100

1.750

00101

1.725

00110

1.700

00111

1.675

01000

1.650

01001

1.625

01010

1.600

VID 4..0

VCore

01011

1.575

01100

1.550

01101

1.525

01110

1.500

01111

1.475

10000

1.450

10001

1.425

10010

1.400

10011

1.375

10100

1.350

10101

1.325

VID 4..0

VCore

10110

1.300

10111

1.275

11000

1.250

11001

1.225

11010

1.200

11011

1.175

11100

1.150

11101

1.125

11110

1.100

11111

Off

--

--

7-8Compaq D315 and hp d325 Personal Computers Featuring the AMD Athlon XP Processor

Second Edition - April 2003

Page 132
Image 132
HP D315 manual LOW Voltage PRODUCTION/DISTRIBUTION, Vid