| 摘要 |
PURPOSE:To charge a load of a large capacity up to a VCC level in high speed, by devising a circuit design in such a way that a positive feedback circuit is stopped until the operation becomes important so as to operate the positive feedback loop efficiently. CONSTITUTION:It is possible to make an E-IGFETT25 conductive and a potential at an output terminal O near the ground level so as to make the positive feedback loop nonconductive, until the gate potential of the E-IGFETT24 is a value near the subtraction of a threshold voltage VT23 of the E-IGFETT23 from a potential VCC, i.e., a value close to (VCC-VT23), by selecting the channel length and the channel width of an E-IGFETT26 suitably. Since the potential difference between the gate and the source of the T24, when the T25 is nonconductive and the positive feedback loop starts the operation, is taken largely as (VCC-VT23) and since the positive feedback loop is operated when the conductivity of the T24 is large, the efficiency is improved and a large capacitance is charged to the VCC level in high speed. |
