1. Have 3 phase ac input with neutral, where each phase voltage goes from, 85V-600Vacrms
2. Need output at 5V/500mA
3. training.ti.com/.../Very_high_Voltage_bias_BK_13-Sept_complete.pdf
page 22 shows external fet operation, but again limited to 1200V, very close, so cant use
4. Anyone have experience in this low power application where size/size constraints? Any reference design?
Transformelss is preferred (sealed application), size and sace constraint.