Other Parts Discussed in Thread: UCC28C42
I am coming up with a multi-output bench PSU design that's inspired by Linear's reference design here. The requirement is for a 3 channel PSU with isolated outputs: two would be 0-32V at 6A and one would be 0-6V at 6A. That Linear (now AD) design pre regulates the incoming voltage with a SMPS which tracks the output voltage +1.7V thus minimizing the power dissipated in the linear stage. I was looking for a suitable TI part to mimic the functionality of the LT8612 in that design. There are a few questions I have:
1. What IC would match the LT8612 but ideally also add isolation? I put the UCC25640-3DDBR in this thread as this is a part that I got from a WEbench design for a 40-50V input, 5V 6A isolated output design but maybe that won't be a good choice as, I'd like to be able to vary the SMPS output between 1.7 and 33,7 V and there's no way to specifiy that in WEbench that I can see.
2. The Linear reference design uses a 40V DC input which could be met by a frame SMPS at 48V, 400W. The idea did occur to me that I could have the switcher circuit in item 1 above regulate all the way from the rectified AC input down to 1.7V (doing away with the need for the frame PSU) but this is probably impractical at the currents I want plus I would still need 3 circuits to get isolation between channels and my PCB would end up having 400V DC on it!
3. Those isolated designs in WEbench give part numbers for cores and a turns ratio for primary and secondaries but, where can I get practical guidance for actual wire gage and number of turns?
Thanks in advance.
