An effective cross-talk isolation structure for power IC applications

Abstract

The simple and effective cross-talk isolation structure consists of an isolator and a collector, and is placed in the epitaxial layer between the CMOS structure and the power device. Results show that, with the use of the isolation structure, operating current of the body diode of the LDMOST can be improved by 16 times and operating current of the LIGBT can be improved by 5 times before CMOS latchup in the control circuit occurs. For dynamic interaction between integrated LIGBTs, 8 times reduction in current surge in the adjacent device during turn-off transient is observed.