SSI America ERP2U - Manual (Page 25)

SSI
ERP2U Power Supply Design Guide, V2.31
- 25 -
may be removed, then replaced with a good power supply, however, hot swap needs to work with operational as
well as failed power supplies. The newly inserted power supply may get turned on by inserting the supply into the
system or by system management recognizing an inserted supply and explicitly turning it on.
6.11 Timing Requirements
STATUS
Required
These are the timing requirements for the power assembly operation. The output voltages must rise from 10% to
within regulation limits (T
vout_rise
) within 5 to 200ms. The +3.3 V, +5 V and +12 V output voltages should start to
rise at about the same time. All outputs must rise monotonically. The +5 V output needs to be greater than the
+3.3 V output during any point of the voltage rise. The +5V output must never be greater than the +3.3V output
by more than 2.25 V. Each output voltage shall reach regulation within 50 ms (T
vout_on
) of each other during turn
on of the power supply. Each output voltage shall fall out of regulation within 400 ms (T
vout_off
) of each other
during turn off. Figure 3 and Figure 4 show the turn ON and turn OFF timing requirements. In Figure 4, the
timing is shown with both AC and PSON# controlling the ON/OFF of the power supply.
Table 24: Output Voltage Timing
Item Description MIN MAX Units
T
vout_rise
Output voltage rise time from each main output. 5 200 ms
T
vout_on
All main outputs must be within regulation of each
other within this time. 50 ms
T
vout_off
All main outputs must leave regulation within this
time. 400 ms
Vout
10% Vout
T
vout_rise
T
vout_on
T
vout_off
V1
V2
V3
V4
Figure 3: Output Voltage Timing