Integrated circuit configuration for driving a power MOSFET with a load on the source side

摘要

Field-effect-controllable power semiconductor components with a source- connected load are made conducting via a control circuit with an integrated charge pump. When a generator connected to the source side is in operation, then the source potential becomes higher than the drain potential. A parasitic diode therefore carries current in the control circuit. That current turns on a parasitic bipolar transistor that limits the gate potential to a value that is no longer sufficient for making the power semiconductor component conducting. This effect is prevented by connecting a further diode in antiseries with the parasitic diode.