| 摘要 |
PURPOSE:To enable to operate even at low power supply voltage, by constituting the circuit with the differential amplifier, current source and first to third FET transistor Tr, and obtaining the inversion current for the current source current from the drain of third transistor. CONSTITUTION:The differential amplifier 10 has the function that the potential at point A is equal to that at point B so that the output 11 controls the conduction of FETQ3, and if the potential at point B is increased, the output 11 increases, and if the potential at point B is increased, the output 11 decreases to compensate the potential variation at point B or C. That is, the potential of point C is in agreement with the potential at point B with the negative feedback loop connected from the output of the amplifier 10 to the inversion input terminal - of the amplifier 10 through FETQ3. The matching of the source and drain voltage of FETQ1 and Q2 is remarkably excellent and the matching is kept even to the load and power supply fluctuation connected to the output terminal A of the inversion current, and the potential at point B is the drop only for the gate source voltage of FETQ1 from the power supply. Accordingly, the low power supply operation can be made. |
