Impact of using too less substrate tap

[diarmuid]

Hello All,

I am laying out a bandgap. Apart from latch-up, what is the impact of uisng too less substrate tap?

Thanks,

Diarmuid

 

[jirika]

Increase of noise comming from sub, if there's block injecting a lot of charge into sub - substrate voltage shift and so on

 

[berkeleyanalog]

Increase of noise comming from sub, if there's block injecting a lot of charge into sub - substrate voltage shift and so on

For this reason you should make a guard ring out of your substrate taps, ideally around each individual BJT as well to catch injected minority carriers.