Hi ADI members:
Attached file is my circuit: Vbus 380V / 24Vout which was modified from DC1929A circuit. Here is my problem: when 380V input, the house keeping power start switching. But the SS1 reset with the VHK = 13.8V. If I use external DC source to input VHK=13.9V & Vuvlo_vsec=1.3V , the SS1 can power up.
Would you please help.