| 摘要 |
PURPOSE:To perform stable action of high response with high accuracy adding an FET newly to a constant current source which is constituted of an FET and a reference resistance, and compensating the characteristics of the original FET owing to the fluctuation in load or source voltage. CONSTITUTION:The source of an FET2 and the drain of an FET1 are connected, and the source of the FET1 is connected to one end of a reference resistance R. Another end of the reference resistance R is an output terminal 12. The gate of the FET2 is connected to the source of the FET1 and the gate of the FET1 is connected to the output terminal 12. The power source V of the input terminal 11 is connected to the drain of the FET2. With such constitution, the FET2 is so connected that its gate voltage VGS2 is made equal to the drain voltage VDS1 of the FET1. Hence, when a load resistance RL decreases or the source voltage +V increases, the voltage VDS1 is negated by the voltage VGS2, and the current ID flowing in the resistance RL is made constant with high accuracy. The stable action of fast response is performed. |
