| 摘要 |
PURPOSE:To reduce an induction current and to accelerate responsiveness by using a specific semiconductor device as an impedance device to supply a bias voltage to a driving transistor. CONSTITUTION:The device described below is used as the impedance device 4 which permits a charge current to flow on a capacitance between the gate and the source of an output MOSFET at a transient time when an input signal is generated, and supplies the bias voltage to the driving transistor(TR) of normally ON type connected between the gate and the source of the output MOSFET at a normally operating time when the input signal is stabilized. A diffusion area 40 where P-type impurity with high density is diffused is formed in an N-type impurity semiconductor area 44 with low density wrapped by an insulating film 45 on a substrate 46, and its surface is covered with an insulating film 47. voltages 41 and 42 are connected to both ends of the area 40. The P-N junction between the areas 40 and 44 is reversebiased at the time of generating a photovoltaic force, and a depletion layer is diffused. When a reveres bias voltage exceeds a prescribed value, the depletion layers are connected in the area 44, and the current flows on a meandering resistance pattern in the area 40 in a direction of (A-A'). then, resistance can be decreased. |
