650V SOI LIGBT for Switch-Mode Power Supply Application

This paper presents a thin-layer high voltage silicon-on-insulator conductivity modulated device which has been optimized for use within integrated switch mode power supply applications. The device contains a linearly-graded charge profile in the drift region, and the fast-switching LIGBT can be used at current densities which are at least a factor-of-two greater than the SOI LDMOS of equivalent breakdown voltage (LIGBT BV_ds 650V/R_sp 4 ohm mm²). A device failure mechanism which occurs during shorted-winding SMPS transients unique to thin-layer devices has been documented, and device protection circuitry has been developed to provide a transient current limit mechanism within the high voltage device. The electrical characteristics of the protected conductivity modulated thin-layer SOI high voltage device are comparable to state-of-the-art discrete components, and as such this process technology provides a monolithic alternative for miniaturization and integration of switch mode power supply topologies