Low Voltage Distribution; Figure 7-4. Low Voltages - HP Deskpro EX Technical Reference Manual

7.2.2 LOW VOLTAGE DISTRIBUTION

Voltages less than 3.3 VDCincluding processor core (VccP) voltage are produced through
regulator circuitry on the system board.
Type Det-
AGP Bus
Power Supply
Processor
NOTE:
[1] VDDQ = 1.5 for AGP 4X cards (Type Det- grounded).
= 3.3 for AGP 1X/2X cards (Type Det- left open).
Figure 7–4. Low Voltage Supply and Distribution Diagram
The VccP regulator produces the VccP (processor core) voltage according to the strapping of
signals VID3..0 by the processor. The possible voltages available are listed as follows:
Refer to Chapter 3 for a listing of the core voltages set by the Celeron (Table 3-1) and Pentium III
(Table 3-2) processors.
+5 AUX
RAM PWR
+5 VDC
AGP PWR
+5 VDC
Regulator
+3.3 VDC
Regulator
+5 VDC
+12 VDC
VID0
Regulator
VID1
VID2
VID3
VID 3..0 VccP
0000 2.05 VDC
0001 2.00 VDC
0010 1.95 VDC
0011 1.90 VDC
0100 1.85 VDC
0101 1.80 VDC
0110 1.75 VDC
0111 1.70 VDC
Compaq Deskpro EX Series of Personal Computers
First Edition - August 2000
S3 Mode
3.3 VDC
Circuit
VDDQ [1]
LM317
2.5 VDC
Circuit
+3.3 VDC
VTT (+1.5)
Circuit
VccP (see text)
Circuit
VID 3..0 VccP
1000 1.65 VDC
1001 1.60 VDC
1010 1.55 VDC
1011 1.50 VDC
1100 1.45 VDC
1101 1.40 VDC
1110 1.35 VDC
1111 1.30 VDC
Technical Reference Guide
DIMMs
AGP Bus
Pull-Up Logic
Processor
7-7