| 摘要 |
PURPOSE:To keep stable switching and stable high speed chopper control even in the case of a load whose resistance changed considerably by making a power NMOSFET conductive and nonconductive not through a load. CONSTITUTION:An electric charge is supplied (charged) to a stray capacitor 24 in existence between a gate and a source of a power NMOSFET 11 not through a load 51. Thus, an event of an increase in a source level due to the existence of the load 51 is not caused and a gate voltage is not boosted over the voltage of a power supply 61, then the applied voltage between the gate and the source is ensured to make the drain and source of the power NMOSFET 11 conductive. Thus, even in a remarkable change in a load resistance or independently of the load resistor size, smooth and stable switching operation (load drive control) and high speed chopper control of the power NMOSFET are always attained. |
