| 摘要 |
A high-current VMOS transistor having a source connected to a floating reference voltage terminal is switched between conducting and non-conducting states by a low power source including complementary-symmetry FET's. When the VMOS is back biased a low impedance path having a constant predetermined voltage exits between the VMOS source and drain via one of the bipolar transistors. This prevents false triggering of the VMOS if the reference voltage drops below a nominal value. A diode polarized to pass current oppositely from the source drain path and in shunt with the source drain path prevents the VMOS from conducting if the reference voltage rises above the nominal value. The bipolar transistors are shunted by a zener diode to maintain a predetermined voltage across the bipolar transistors, i.e. between the reference voltage terminal and a terminal connected through a load resistor to a power supply terminal.
|
