power sequence question

[only_lonely]

need to conduct DC margin test using Agilent MAINFRAME ( have +5V,+3.3V,+12V,-12V,Power GD,+24V modules).
then take out the power supply from my motherboard, connnect those modules to my board ,simulate the power supply condition.
But the staff told me to calculate or figure the time for those AC voltage....
power sequence for the board to make the board fully function.
But does the power sequence really important? it seems the interval time is only <20miliseconds..
Can i know whats the theory inside?

 

[indulis]

It's not the sequence of the power supplies themselves that is important, but it could be VERY important to what they are "powering-up". For example, some CPU's are very particular in what order it see's which voltage.

 

[only_lonely]

so,
if i want to enter the time for those voltage to power up my mobo.
which spec i should refer to, the motherboard or power supply?

 

[indulis]

The motherboard.

There are electronics someplace that control the "power-up" sequence and type. Are you trying to margin test the voltage, or the sequence time?