| 摘要 |
PURPOSE:To drive a load with a stable drive voltage regardless of the fluctuation in a power supply voltage. CONSTITUTION:Impedance elements 4 and 5 connected in series are connected in parallel to a motor 3 and a comparison circuit 7 compares the voltage of a connection point A of each impedance element with a reference voltage and generates an output voltage corresponding to the difference. A drive signal generation circuit 8 alternately applies first and second drive signals to the gate of a first MOS transistor TR1 of first and second series circuits to drive the motor. A first switching circuit 9 and a second switching circuit 10 are turned on by the first and second drive signals, the output voltage of the comparison circuit 7 is applied to the gate of a second MOS transistor of the first and second series circuits, thus retaining the drive voltage of the motor 3 at a desired value. |
