HV process, without npn do a bandgap,,

Hi all:
I am doing a project, 32v hv process without npn transistor, just have 12v npn transistor, how can i generator a bandgap voltage?
Vbe/R current can be got, but other circuitry?
Thank you help....................

You can use ptat with NMOS transistors delta(VGS) ..

You can use ptat with NMOS transistors delta(VGS) ..?

12v npn 难道不能用么?12v指的应该是最高耐压啊