RF immunity investigations of linear DC current regulators

This paper studies and compares the RF immunity of DC current regulators against electromagnetic interferences (EMIs). The effect of EMI on the performance of a classic topology is analyzed. It turns out, especially the regulators output is very sensitive against EMI since disturbance levels in the millivolt range cause serious malfunctions. Subsequently the paper introduces a structured approach to the design of EMI resistant regulators. RF immunity measurements on IC level (DPI) and on system level (BCI) proof the superior EMC performance of the resisting topologies over the classic regulator, while the electrical characteristics and the area of the circuits are the same. The circuits have been designed using a HV- BiCMOS technology for automotive applications.