Intel EPS1U manual Timing Requirements, Output Voltage Timing

SSI

EPS1U Power Supply Design Guide, V1.1

6.9Timing Requirements

STATUS

Required

These are the timing requirements for the power supply operation. The output voltages must rise from 10% to

within regulation limits (Tvout_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 (Tvout_on) of each other during turn on of the power supply. Each output voltage shall fall out of regulation within 400 ms (Tvout_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
Tvout_rise	Output voltage rise time from each main output.	5	70	ms
Tvout_on	All main outputs must be within regulation of each		50	ms
	other within this time.
T vout_off	All main outputs must leave regulation within this		400	ms
	time.

Vout

10%

Vout

V1

V2

V3

V4

Tvout_rise Tvout_off

Tvout_on

Figure 4: Output Voltage Timing