I built a flybuck auxiliary power supply using LMR38020FDDAR, which outputs two 12V. The designed non isolated 12V_ANA output power is 12W, and the isolated 12V_H output power is 3W. The voltage of the non isolated 12_ANA does not change with the change of load R47 (I use resistance to simulate the load), but the isolated 12V_H decreases with the decrease of load resistance R45. When R45=46.9 ohms, the voltage drops to 7.5V. Why did this phenomenon occur, where did the problem occur, and how should I solve it.
Thank you so much.
