| 摘要 |
PURPOSE:To improve frequency characteristics and to attain load drive with high gain by actuating the FET of an input source follower stage at a saturated area. CONSTITUTION:MOSFETs-M1 and M2 form an input source follower stage and an output source follower stage respectively. A FET-M1 works by using the source voltage of a FET-M2 as the drain voltage. In this case, the FET-M1 works at a saturated area as long as the value obtaned by subtracting the source voltage of the FET-M2 from the gate voltage of the FET-M1 is smaller than the threshold voltage of the FET-M1. Therefore, the current value I0 of a current source 2 is set at a prescribed level. Thus the FET-M1 works at the saturated area, and each gate voltage is held approximately at the same potential as each source voltage. Then the gate/drain capacity of the FET-M1 is reduced. This improves the frequency characteristics. |
