On the Key Role of the Brokaw Cell on Bandgap Immunity to EMI

In this paper the immunity of a Brokaw bandgap towards electromagnetic interferences superimposed to the supply voltage is investigated. The attention has been focused on the bandgap cell itself, verifying that it is the main responsible of device performance degradation in the presence of radio frequency noises. The bandgap model is firstly validated comparing experimental measurements with computer simulations, using both S-pararneters and susceptibility analyses. The most important stray components responsible for a correct susceptibility prediction are highlighted. Finally some suggestions to possibly reduce the bandgap susceptibility are presented at both design and layout/technology level.