Discussion of the Immunity of a Brokaw Bandgap to EMI

In this paper, the susceptibility of a Brokaw bandgap voltage reference towards Electromagnetic Interferences (EMI) superimposed to the power supply is investigated. The attention is focused on the bandgap cell itself, verifying that it is the main responsible for the device malfunction when radio frequency noises are injected in the chip through the supply rail. In particular, the rectification phenomena of bipolar transistors, used in the bandgap cell, are proved to cause the voltage reference performance degradation. Some possible hints to overcome this problem are also explored, suggesting design modifications, filtering solutions and layout changes.