| 摘要 |
PROBLEM TO BE SOLVED: To obtain a simple and low cost current output device for outputting a current to an external load by amplifying an input signal, while reducing power consumption by suppressing increase in the collector-emitter voltage of a transistor for amplification.SOLUTION: A current output device for outputting a current to an external load by amplifying an input signal has a voltage control section outputting the power supply voltage supplied from a power supply, while amplifying, to a transistor for amplification, a FET which is turned on when the collector-emitter voltage of a transistor for amplification exceeds the threshold gate-source voltage thereof, and outputs a drain current, and a voltage detector for generating a step-down voltage and a reference voltage proportional to the drain current, and outputting them to the voltage control section. The voltage control section controls the step-down voltage so that the reference voltage outputted from the voltage detector is maintained constant.SELECTED DRAWING: Figure 2 |
