Improving the immunity of smart power integrated circuits by controlling RF substrate coupling

This paper discusses RF substrate coupling in smart power integrated circuits. Analyses have been accomplished by measurements on wafer level. For this purpose test structures have been designed using a BCD technology (Bipolar, CMOS (complementary MOS) and DMOS (double diffused MOS)) for automotive applications. The determining parameters to RF substrate coupling have been evaluated by measuring structures with two transistors. The findings are applied to a typical smart power integrated circuit. It results in controlling RF substrate coupling and a circuit with a high degree of immunity against electromagnetic interference (EMI). The paper closes with appropriate layout recommendations.