| 摘要 |
PURPOSE:To obtain a current source of high output resistance, by connecting the drain and the gate of the second MOSFET to the source of the first MOSFET where a DC voltage is applied to the gate. CONSTITUTION:A D type MOSFET11 and an E type MOSFET12 are connected in series between power sources 10 and 20 to constitute a bias circuit. An output voltage 15 of the bias circuit is connected to the gate of an E type MOSFET13, and the drain of the FET13 becomes an output terminal 30. An E type MOSFET 14 where the gate is connected to the drain is connected between the source of the FET13 and the power source 20. When the voltage of the output terminal 30 becomes higher, the current of the FET13 tries to rise by the channel length modulation effect; however, the voltage drop of the FET14 is increased, and the source potential of the FET13 rises to suppress the increment of the current. |
