Intel EPS1U - Manual (Page 20)

SSI
EPS1U Power Supply Design Guide, V1.1
6.9 Timing Requirements
STATUS
Required
These are the timing requirements for the power supply operation. The output voltages must rise from 10% to
within regulation limits (T
vout_rise
) within 5 to 70 ms. 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 +5 V 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 4 and Figure 5 show the turn ON and turn OFF timing requirements. In Figure 5 the timing
is shown with both AC and PSON# controlling the ON/OFF of the power supply.
Table 15: Output Voltage Timing
Item Description MIN MAX Units
T
vout_rise
Output voltage rise time from each main output. 5 70 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 4: Output Voltage Timing
Vout
10%
Vout
T
vout_rise
T
vout_on
T
vout_off
V1
V2
V3
V4