Selecting AUX power controller or flyback IC

Hi expert,

I need your help to selecting an AUX power controller or flyback IC for my customer. Better have TI design for them.

1.      VAC input = 480Vac or VDC input = 400~1000V，V output =12V*4A = 48W

2.      Stable frequency= 65kHz, have burst mode in light load condition

3.      brown out protection function, pin protection.

Thanks

Sheldon