Solution Finder Get Tech Support

100V - 450V Input - 14V Output @ 5A PSU

Posted by: harrym on

I am enquiring about the possibility of using one of your devices for an isolated power supply with the following characteristics.

Input - 100VDC - 450VDC
Output - 14VDC @5A

I have seen DER-276 which details the use of a Topswitch to create a similar supply however the power and maximum input voltage are not as high as required by my intended application.

I would be grateful if you can provide me with information on which devices may be suitable for this application.

Kind Regards,
Harry

Comments

Submitted by PI - Traveler on 01/25/2012

Harry -


At 450VDC input, you should still be able to put a design together without having to use the additional series FET that you're referring to (from some of our power meter application circuits).


Using PI expert, you can enter in a maximum of 425V DC for your input which should get your pretty close. You can use PI Expert in conjunction with PI XLS to put together this design. In PI XLS, you're limited to an AC input but it's fairly easy to work around. Just use a really large input capacitance value (999999999999 uF for example) and then adjust your min/max AC inputs until you get Vmin = 100 VDC and Vmax = 450 VDC.


PI Expert will make choosing the correct device and transformer easier. PI XLS will give you a bit more control over being able to manually set values for parameters like the number of primary layers, VOR, secondary turns, etc. Then you can go back into PI Expert and use the information from PI XLS to figure out your clamp circuit components, feedback components, etc.


Again, this isn't strictly supported by the software but as long as your peak drain voltage is below BVDSS (700V) you're technically ok. You'll want to keep VOR (your output reflected voltage) on the low side (probably less than 100V) and you'll want to put some time/care into your transformer design. Specifically, you'll want to minimize your leakage inductance to keep your peak drain voltage down and also minimize your clamp losses.


Hopefully, that will get your started. If you have questions, feel free to ask. If you're stuck and can give me some of your requirements (transformer size limitations, specific feature requests, etc), I can probably put together a quick design in PI XLS and PI Expert for you. Again, this is a corner case scenario that totally covered by our design software...but I should be able to get you to a good starting point if you need additional help.


-The Traveler