Other Parts Discussed in Thread: UCC24624
Tool/software:
I am designing a +/-160 Volt @ 5A with a +/-24V 3A for positive 24V and 1A for -24V power supplies with synchronous rectification and I have a couple of queries.
UCC256404 – I have used the UCC256404_LLC Design_Calculator.xlsx to design the LLC as well as a web bench for 160V @ 5A design. I have also amended a simplis schematic with the values from the spread sheet. The issue I am having is that I appear that have a very low gain cross over frequency of around 400Hz, also when using the values given in the web bench design, I get crossover frequency of 100Hz with a phase margin of 81 degrees. My understanding is that I need a cross over frequency of 1/5 to 1/10 of the switching frequency. I don’t know if I am doing something wrong.
UCC24624 – I am intending to use a synchronous controller (UCC24624) for synchronous rectification of the positive and negative rails. From a basic understanding for synchronous rectification of the negative supplies if I provide an isolated voltage 12V above the negative rail voltage this should work, does anybody know if my assumption is correct.
I can supply spread sheet and web design if needed.
Regards
Ian
