SSI
EPS2U Power Supply Design Guide, V2.1
Contents
1
Purpose.......................................................................................................................................................... 5
2
Conceptual Overview ................................................................................................................................... 5
3
Definitions/Terms/Acronyms....................................................................................................................... 6
4
Mechanical Overview ................................................................................................................................... 7
4.1
Airflow Requirements .................................................................................................................................. 8
4.2
Temperature Requirements ........................................................................................................................ 8
5
AC Input Requirements................................................................................................................................ 9
5.1
AC Inlet Connector...................................................................................................................................... 9
5.2
AC Input Voltage Specification ................................................................................................................... 9
5.3
Efficiency..................................................................................................................................................... 9
5.4
AC Line Dropout........................................................................................................................................ 10
5.5
AC Line Fuse ............................................................................................................................................ 10
5.6
AC Inrush .................................................................................................................................................. 10
5.7
AC Line Transient Specification................................................................................................................ 10
5.8
AC Line Fast Transient Specification........................................................................................................ 11
6
DC Output Specification ............................................................................................................................ 12
6.1
Output Connectors .................................................................................................................................... 12
6.1.1
12V Power Rail Configurations.......................................................................................................... 12
6.1.2
Baseboard power connector.............................................................................................................. 13
6.1.3
Processor Power Connector.............................................................................................................. 14
6.1.4
Peripheral Power Connectors............................................................................................................ 15
6.1.5
Floppy Power Connector ................................................................................................................... 15
6.1.6
Server Signal Connector.................................................................................................................... 15
6.2
Grounding.................................................................................................................................................. 16
6.3
Remote Sense .......................................................................................................................................... 16
6.4
Output Power/Currents ............................................................................................................................. 17
6.4.1
Standby Outputs ................................................................................................................................ 18
6.5
Voltage Regulation.................................................................................................................................... 19
6.6
Dynamic Loading ...................................................................................................................................... 20
6.7
Capacitive Loading.................................................................................................................................... 20
6.8
Ripple / Noise............................................................................................................................................ 21
6.9
Timing Requirements ................................................................................................................................ 21
7
Protection Circuits...................................................................................................................................... 24
7.1
Current Limit.............................................................................................................................................. 24
7.2
240VA Protection ...................................................................................................................................... 24
7.3
Over Voltage Protection ............................................................................................................................ 25
7.4
Over Temperature Protection.................................................................................................................... 25
8
Control and Indicator Functions ............................................................................................................... 26
8.1
PSON# ...................................................................................................................................................... 26
8.2
PWOK (Power OK) ................................................................................................................................... 27
8.3
Field Replacement Unit (FRU) Signals ..................................................................................................... 27
8.3.1
FRU Data ........................................................................................................................................... 27
8.3.2
FRU Data Format............................................................................................................................... 28
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