Tool/software:
Hello,
I'm working on a 48V to 3x isolated 28V @ 0.2A flyback converter, using LM5158 and a Pulse VPH5-0155-R or Wurth 749196518 1:1:1:1:1:1 transformer with ~23µH primary inductance.
Please could you advise on the practical upper switching frequency limit for this application?
I have seen "2200kHz is way to high for a flyback." on a comment on a different ticket - https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1428045/lm5158-lm5158?tisearch=e2e-sitesearch&keymatch=LM5158%20flyback#
Most flyback reference designs seem to run 150kHz to 300kHz, but I can't find any information on how to select a practical upper switching frequency, or why 2.2MHz is too high....have tried scouring the internet. If it's due to the limits of the internal FET in the LM5158 (SOA / turn-on - turn-off times), please could you offer some guidance?
Thanks in advance,
Gordon