SSI
ERP2U Power Supply Design Guide, V2.31
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Purpose
This 2U Rack Power Supply Design Guide defines a common redundant power sub-system used in 2U rack
mount servers. The power sub-system is made up of a cage and hot swap redundant power modules. This
Design Guide covers the mechanical and electrical requirements of this power sub-system. The requirements of
the individual hot swap modules are left open. This power sub-system may range from 550 to 800 watts and is
used in a hot swap redundant configuration. The scope of this document defines the requirements for this power
assembly. The parameters of this supply are defined in this design guide for open industry use.
Conceptual Overview
In the Entry server market, the bulk power system must source power on several output rails.
These rails are typically as follows:
+3.3 V (optional from bulk supply)
+5 V (optional from bulk supply)
+12 V
–12 V
5 V standby

NOTE

Local DC-DC converters shall be utilized for processor power, and will ideally convert power from the +12 V
rail, however, they may also convert power from other rails.
The bulk power system may be a n+1 redundant power system or a non-redundant power system.