Output Voltages

Posted by: ljarillas on 05/21/2009

Got a (maybe) simple question. I got the following output requirements:

Out1: 15V @ 1.5A
Out2: 5V @ 1A
Out3: 4V @ 0.5A (peaks at 2A for 577us out of 4.615ms period)

I know that in PI Expert, you just put the two outputs straight-forward w/ the same peak current as that of the continous current.

But with the third output, do i put 0.5A as the continous and 2A as peak? When I do this, PI Expert is having trouble finding me a transformer or a device.

I also noticed on AN-43 that there is a formula for P(ave). Applying this formula to the third output only give me ~3W.

-Thanks.

Comments

Which device family are you using? I tried with Peakswitch and I can get an optimized design. For 30 Watts continuous and 35 W peak you should be using either Peakswitch or Top-HX.
Also, since the difference between the continuous power and peak power is not all that much, it may not be a bad idea to just design for 35 W continuous power.

Hi. I am using Top-HX. I was trying to use PeakSwitch but I cannot get an optimized design.

You can get an optimized design for PeakSwitch as well... YOu will probably need to try from both P and Y package and then try optimizing from both.
Anyways I do think TOP-HX is the better choice in this case because your peak power requirement is really not that much different from the continuous power requirement.