Psu Redundancy - QUANTA W Mainboard Series S210-MBT2W Technical Manual

A S
BOUT THE ERVER
[1.3.237] SMBUS Addressing for PSUs SMBUS ADDRESSING FOR PSUs
P B20 (A1 SMB
IN
D
ESCRIPTION
A
1st PSU closet to the
Chassis Wall (A0)
2nd PSU (A2)
3rd PSU (A4)
4th PSU furthest from
Chassis Wall (A6)

[1.3.238] PSU Redundancy

[1.3.239] The CRPS and ERP1U Power Supplies will automati-
cally switch from a 1+1 configuration to a 2+0 configuration if
the demand for power goes above the PSU rated wattage.
[1.3.240] PSU Signal Connectivity
[1.3.241] Connect the following 3 signals directly between the
PSUs on the baseboard:
[1.3.242] Signals that Connect Directly Between PSUs
P
IN
B22 Cold Redundancy bus
B23 12V load share bus
P B19 (A0 SMB
US IN
) A )
DDRESS DDRESS
0 0
0 1
1 0
1 1
D
ESCRIPTION
[1.3.243] PWOK
US
[1.3.244] The PWOK signals from the power supplies are
bussed together and pulled up to 5Vstby or 3.3Vstby. No glue
logic on the motherboard is needed to process the two PWOK
signal from the power supplies to generate a system PWOK
signal.
[1.3.245] It is important to note that the sink current is 0.5mA
max (SSI spec is 4mA). It is important to size the pull-up resis-
tor correctly in order to meet the max sink current requirement.
If PWOK is connected to 3.3VSTBY, the pull up value might be
larger than 6.8k? and if PWOK is connected to 5VSTBY, it must
be pulled up to something weaker than 10k?. Requirement for
this product is to pull up PWROK to 3.3VSTBY via 8.2k?.
[1.3.246] System PSU Bulk Caps
[1.3.247] The board design needs to account for the load step
size and frequency to determine the size of the bulk caps. As a
starting point, Architecture recommends reserving total space
for 2-3mF (this includes the capacitance of the VR input caps)
for both PSUs.
[1.3.248] PSU Connector
[1.3.249] The Docking Power Supply Connectors are used on
the PDB, and not on the S210-MBT2W baseboards.
1-84
AC P S (
OWER UPPLIES TO BE UPDATED
)