I am using 4 LMG3410R070 devices to form a three-level flying capacitor converter.
When I did experiment for a three-level buck configuration with only 100kHz switching frequency, 30% duty cycle, and simply resistor load 125ohm, the fault signal was always asserted if I increase the input voltage more than 100V (at this configuration the voltage across the device will be only half of the input voltage).
Since the load, I was using is very small, it is impossible to be over current, and also the temperature of the device was maintained bellow 35degrees Celcius, so it's not over temperature neither. Therefore, I think the possible reason causing the fault is only UVLO but I am not sure.
For the voltage supply of the integrated driver, I used a 3W isolated dc-dc power supply with 12V output voltage. And for the bias capacitor of Vdd, I used 1uF MLCC 50V x7R. I also tried to change this bias capacitor to 10uF MLCC 35V x5R but the result was still the same.
It has been a month I am trying to solve this problem but still, I can't figure it out the cause of the fault signal is asserted.
Thank you in advance.