Intel Entry Redundant Power 2U ERP2U User Manual
Page 21
 
SSI
ERP2U Power Supply Design Guide, V1.0
- 21 -
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 2 and Figure 3 show the turn ON and turn OFF timing requirements. In Figure 3, the 
timing is shown with both AC and PSON# controlling the ON/OFF of the power supply. 
Table 18: 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
Figure 2: Output Voltage Timing
Vout
10% Vout
T
vout_rise
T
vout_on
T
vout_off
V1
V2
V3
V4