UCC28070: UCC28070 fed by a variable frequency (100 ... 700 Hz) input voltage

Hello Alexander,

I have tested the UCC28070 at input frequency from 400Hz to 800Hz and the results are attached.

The tests were done on the UCC28070EVM at 115Vac.
I chose that frequency range and voltage because it is the voltage source used on aircraft applications.

I don't see an issue with a lower input voltage, 30-50Vac as in your application.
You will need to scale the VINAC pin input as appropriate.
You will have less output ripple because of the high frequency and you may increase the loop bandwidth for faster transient response as necessary.

I cant answer your question about the Tina model. It may not be accurate at a  high frequency or it may be your circuit model but the UCC28070 will work in this requirement.

What is your application  for such a low input voltage ?

Regards,

John

UCC28070_800Hz.pptx

Hello John,

Your results made at 60..400..800 Hz look good, were there any changes in passives during your frequency span ?

My application is a specific wind turbine, so these frequencies must be well served by the PFC.

As of TINA - I wrote about unchanged TI example, just plain stock taken from TI examples. Input current does looks like there was no PFC at all ...