psu regulator ic supply

[m3vuv]

Hi all,i am building a bench psu (variable),the transfo is from a palstar ps-30 psu,it has an auxillary winding,i plan on using that to power the regulator ic(infinion sg3532)
I have a couple of questions
A,am i best using a 78 series regulator to power the ic?
B,can it be a lower voltage than the main psu output?
TIA.

[m3vuv]

can no one advise on this?.

[inse]

All the application drawings in the datasheet have the IC (Linfinity, btw.) supplied by the input voltage.
If you look at the block diagram, you will notice that the driver is tied to the Vin and thus cannot drive a highside transistor above that voltage.
If you plan on using a PNP, you will encounter a low voltage limit.