NEGATIVE N-EPI BIASING SENSING AND HIGH SIDE GATE DRIVER OUTPUT SPURIOUS TURN-ON PREVENTION DUE TO N-EPI P-SUB DIODE CONDUCTION DURING N-EPI NEGATIVE TRANSIENT VOLTAGE

摘要

A high-side driver in a driver circuit for driving a half-bridge stage having high- and low-side power switching devices series connected at a switched node, the high-side driver driving the high-side power switching device The high-side driver including first and second complementary switched MOSFET series connected at a highside node, driving the high-side power switching device, one of the MOSFETs having a parasitic bipolar transistor formed between the substrate, an N+ epitaxial region connected to the high-side driver supply voltage and the switched node, with the parasitic transistor having a base electrode formed by the N+ epitaxial region, an emitter electrode formed by the substrate and a collector electrode formed by the switched node, such if a transient voltage that is negative with respect to the substrate is present at the highside driver supply voltage, the parasitic transistor will conduct a short circuit current between the switched node and the substrate.