| 摘要 |
PURPOSE:To drive a driving circuit without fail even when the voltage of a driving power source is fluctuated by controlling the current value of a reference current in correspondence to the voltage fluctuation of the driving power source. CONSTITUTION:First reference current generation circuits 3 connected to a first power supply input terminal T1 and a second reference current generation circuit 11 connected to a second power supply input terminal are provided. Then, a control circuit 13 is provided to control a second reference current I01+i2, which is outputted from the second reference current generation circuit, based on a voltage Vcc2 of a second power supply input terminal T2. Namely, when the second reference current I01+i2 to be outputted from the second reference current generation circuit 13 is controlled based on the voltage Vcc2 of the second power supply input terminal T2, the second reference current I01+i2 can be controlled as needed to the change of the voltage Vcc2. Thus, even when the voltage Vcc2 of the second power supply input terminal T2 is fluctuated, the driving circuit to be driven by the second reference current I01+i2 can be driven without fail. |
