Hey,
I have built up some LM2576T-5.0 to convert 12V from a car battery to 5V.
But now I need more than 3A. Is it possible to put some of these LM2576T-5.0 circuits in parallel order?
Or can this cause some problems with the PWM or something like that?
Because I need this very fast I can't buy a bigger voltage regulator...
I hope you know if this is possible - I already wrote to TI but they said I'm "too small" to give support to...
Thanks for your reply,
Manuel
Hi Manual,
Admittedly I do not have any experience with the LM2576 device but there are some pre-requisites when it comes to parallelling converters. The converter must be capable of pre-bias start up (not mentioned int he LM2576 data sheet as far as I could see), remote sense (the FB pin is available so that's good), and the ability to source current but not sink it (converters that have synchronous rectification tend not to play nice with parallelling).
TI has a couple of load share controller devices and several application notes and seminar papers written on paralleling converters. I would recommend looking at the UCC39002 for a start and then there are Power Supply Design Seminar papers on paralleling converters (Sem 800 and Sem 1500 have topics on this). Unfortunately even I have difficulty finding the Seminar topics on the TI website but I have an alternate link that I use to find for all of the Seminar papers from Unitrode/TI (http://www.smps.us/Unitrode.html).
I hope this helps.
Lisa Dinwoodie
Manuel,
Unfortunately, the LM2576 family of parts are not designed to current share. It can be done, but additional external load share control will be needed. I recommend using a higher current part such as the LM22678 or LMZ13605.
Regards,
Allan
Thanks for your responses!
Ok, this seems to be pretty complicated.
I need the LM2576 to feed a long LED strip. Then I will cut this strip into pieces and feed every single part of it with one LM2576.
This will need much more cable but it seems to be the best way.