Semiconductor diode circuit arrangement as wrong-polarity protection stage for electronic circuits e.g. for vehicle airbag system

摘要

The circuit (1) has a MOSFET (T2) for the polarity protection stage, its drain coupled to the positive input (2) of the circuit, its source coupled to the positive output of the circuit and its gate connected to earth. The circuit may have a pair of transistors (T1,T3) providing a comparator, the emitter of one coupled to the drain of the MOSFET and the emitter of the other coupled to the MOSFET source, their collectors coupled to earth via respective resistors (R1,R2).