Hi
My design currently gets FAULT trips and there a few things that I want to change, but also a few things that i am not sure about. here is 1/4 of my H-bridge. The other parts of it is identical.
Each power level has a well decouple 2W isolated power supply. I currently switch at around 100 khz. I have around 100ns deadtime. As my bus voltage gets to around 200V one of the FAULT_BL signals triggers and turns of my system. There is hardly any temperature rise on the LMG3410R070 and i have no reason to believe that there is anything wrong with my 12V supplies as the entre system draws less than 2W (that is 3 isolated 2W supplies plus an MCU plus some LEDs).
* I intend to change my RDRV resistor to around 40K
* I have also added a RC filter on PSFB_BL before the isolator
However when i Look in the datasheet, section 9.2 it is not entirely clear what RC filter i should add as there is one filter before the isolator and an identical one before the LMG3410R070. The datasheet is a little unclear in section 9.2.2.2 (signal level shifting) on what filter is needed.
The name "PSFB" is by the way not valid any more. This is a frequency controlled H-bridge that is regulated to do ZCS.
Can you give me some pointers of what i have missed here.
Best regards
Martin