15 Midplane: Description/Voltages; Warnings And Cautions; Midplane Features; I 2 C Bus - Intel AC450NX Product Manual

15 Midplane: Description/Voltages

This chapter describes the midplane.

Warnings and Cautions

Only a qualified service technician is authorized to remove the server covers and to access any
of the components inside the server. Before removing the covers, see "Safety Guidelines" on
page 115.

Midplane Features

The midplane distributes the power load—CPU and PHP I/O baseboards, memory modules,
peripheral bays, and hot-swap hard disk backplane—among two or three 750 watt autoranging
power supplies. It also provides a bus interface for the CPU and PHP I/O baseboards, memory
modules, and the hot-swap hard disk backplane. The midplane provides the following voltages
and maximum currents:
Voltage
+12 V
+5 V
+3.3 V
5 V standby
-12 V
+24 V Bias
2
I C Bus
2
The private I C bus monitors failures and voltage margining in the server. The 5 V standby
voltage provides power for the bus, and it is available even when the server power is off.
Maximum Current
56 A
68 A
61 A
1 A
1 A
100 mA
171