Hi, I used LM5072-80 as an isolated power for my board, which is in RAUX input mode and not for PoE application. Input voltage range is 18-72V and output is 3.3V. The schematic is almost the same as Figure32 in datasheet. But the 3.3V waveform is sawtoothed and the PWM of LM5072 is not continuous.
The PWM and 3.3V waveform are showed as follows. The PWM frequency is about 250kHz. I attached the schematic also.
I know LM5072 is an old device and I will replace it with a new one in my new design. But I want to know the reason that resulted in this problem. And maybe I can avoid it in my new design.
So can you tell me which is the reason resulted in the sawtooth output? Thanks.
