Reverse polarity protection circuit

A circuit member comprising:

• an inner switching arrangement (4) having an operating voltage line (3) and a ground connecting line (5) configured to connect on a switching circuit (2) a ground contact (12) to said inner switching arrangement (4);
• a reverse polarity protective device comprising a protective transistor (6) arranged in said ground connecting line (5);
• wherein during normal operation, defined by having an operating voltage (Vdd) applied to said operating voltage line (3) and by having a ground potential applied to said ground connecting line (5), said protective transistor (6) is in a conducting state;
• wherein in a reverse polarity situation, defined by having said operating voltage (Vdd) applied to said ground connecting line (5) and by having said ground potential applied to said operating voltage fine (3), said protective transistor (6) is in a non-conducting state;
• and
• wherein said protective transistor (6) is configured to carry a high operational voltage in said reverse polarity situation;
• wherein said protective transistor (6) is a MOSFET comprising in said normal operation a drain, a source, and a gate, wherein said source comprises a source region (16) with a source electrode (9) embedded in a tub-shaped well (19), wherein said tub-shaped well (19) is of identical conductivity type as said protective transistor (6) but of opposite conductivity type as a substrate (20) of said protective transistor (6);
• an output transistor (15) having a source electrode (14) configured to be directly connected to the ground contact (12) during normal operation;
• and
• wherein said output transistor (15) and said protective transistor (10) are substantially identically configured to be switched off in said reverse polarity situation and to receive an overvoltage between a drain-source path.