Compaq 4000N - Manual (Page 139)

Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997
7-5
7.3.2 LOW VOLTAGE DISTRIBUTION
The system board includes a provision for producing 2.5 VDC for microprocessors that require
such a level for core power. The low voltage circuitry (Figure 7-3) consists of a power MOSFET
and regulator components that produce 2.8 VDC, plus or minus 3.57%.
Figure 7–3. Low Voltage Supply, Block Diagram
Microprocessor
+3.3 VDC +2.8 VDC
2.5 V Proc. Detect
Regulator
Circuit
+12 VDC
Power Supply
Assembly
Microprocessor
2SK1388