Can someone give me a brief overview of what logic I would use to select between the UCD3138 and the UCD3020 .
My target application is an off-line Resonant LLC stepping 400VDC down to 24V with output power around 1.5kW. So probably full bridge drive and synchronous rectifiers on the output. I am also looking for some more advanced options like constant power limiting that are difficult with the analog only controllers.
I see there is a nice LLC EVAL board on the UCD3138. So that alone make the UCD3138 slightly more attractive.
The biggest difference I see is the feedback compensator - 2p/2z PID for the UCD3138 verses 3p/3z for the UCD30xx. I would expect a greater range of phase compensation with the latter but are there down sides to that scheme?