| 摘要 |
PURPOSE:To enable the reduction of an output strain by providing means for making ON resistor of reverse direction between one source and drain of two MISFETs forming the output circuit of a PWM system to accord with ON resistor of forward direction of the other source and drain. CONSTITUTION:In order to make one ON characteristics of a diode between one source and drain of P-channel and N-channel MISFETs connected complementarily to so as to match the ON resistor of the other channel part, means for increasing the voltage drop in forward direction of the diode is provided. For example, in the N-channel MISFET, a thick P type wafer is used with high resistance as a substrate 7, thereby increasing the resistance of the substrate. The substrate is connected partly at 7a to a source, but connected mostly at 7 to an insulator 8 is non-ohmic state. Thus, bias current is limited, thereby increasing the rising voltage in reverse direction. |
