Kind experts,
Regarding the TPS40054 TPS40055 TPS40057 ....
In another post, to this forum, I found the correct equation to use for R_LIM and Ioc (use the formula in the data sheet, not the app note SLUU190 ).
Good.
Having run that equation, I see one potential problem with my FET of choice. In my preliminary design, the Rds_on of the FETs was really low, about 2mOhm. The circuit appears to be functional, but it will be harder to express a voltage drop on the top-side FET for current-limit.
Please provide guidelines on FET selection for this chip family. feel free to point me to something already in the forum. I did look, and all I could find was a warning about Rds_ON being too low for the TPS40057 application, where it plays into the zero-cross detector.
Cheers!
Michael A. Banak