Newbie question: Is it possible to design band gap voltage ref without BJT?

[vadim888]

so my quiestion is:
is it possible to design bandgap voltage reference without BJT? only using MOS transistors.

if so, could you please give me a link to the solution

 

[nguyenvanthien]

It is very possible:-D.
You can refer the paper " A bandgap voltage reference with only mos transistor" or search google to find more documents.

 

[dick_freebird]

Yes, people often use the substrate PNP (because it happens
to be in the right electrical orientation for a ground-referred
bandgap design.

In standard Psub/Nwell CMOS, the P+/Nwell (which you want
for a groiund-referred design) is really a substrate PNP, no
getting around that (absent SOI or deep Nwell with enough
of a buried layer or retrograde doping that the PNP base is
effectively dead).

 

[d123]

Hi,

What Dick-freebird said about substrate BJTs as bandgaps appears in the one called "Bandgap reference" on pages/slides 15 and 17 (17 is the parasitic PNP one), it has explanatory diagrams so I was able to understand it a bit.

MT-087 shows diferent ways of making them, not all were BJT-based.

View attachment MT-087.pdf

View attachment Bandgap-reference.pdf