Specifications

9 March 1999 – Subject To Change

Functional Description 4–19

DC Power Distribution

Vdd (+5.0 V) is supplied to ISA connectors, PCI32 connectors, and most of the

board’s integrated circuits. Vdd also drives the +2.5-V regulator, which supplies the

21164 microprocessor.

Figure 4–10 AlphaPC 164LX Power Distribution

ISA Conn. PCI32 Conn.

Pull-Downs

+5-V Pull-Ups

Integrated

Circuits/Clocks

Spkr

+3.3-V Pull-Ups

Fan

21164

pc164lx.2

FM-05953.AI4

J2, J19

P/J18

+5 V (Vdd)

+12 V

-12 V

-5 V

+2V

Gnd

pc164lx.20pc164lx.23

PCI64 Conn.

pc164lx.21

Power

Connector

pc164lx.31

Fans

Flash

+3.3 V

+2.5-V

Regulator

pc164lx.32

3,5,7,13

4,6,19,20

1,2,11

15,16,17

pc164lx.28