| 摘要 |
PURPOSE:To make the entire current of the titled circuit nearly zero when an input signal of a power voltage level or so is given by providing the 1st control circuit controlling a current level of a constant current circuit and the 2nd control circuit inputting an input level signal and controlling the 1st control circuit. CONSTITUTION:When a signal VI1 is at the TTL level, since an effective voltage between a gate and a source of an element P4 is large, no effect is given to a control system comprising elements P3 and N4. When the level of the signal VI1 approaches a level VD1 gradually, since the capability of the element P4 is deteriorated, a current flowing to a control circuit system comprising the elements P3, N4 is suppressed, the potential at a point 5 is increased gradually and the potential difference between the points VD1 and 5 reaches a threshold voltage of the element P2 or below and a current of a constant current circuit comprising the elements P2, N2 and N3 is lost. On the other hand, the gate-source voltage of the element N1 is increased much larger, that is, since the capability of the element N1 is increased gradually, the level of a point Vo1 is drawn to a common potential VS1. Thus, when a power voltage level is given to the input, the current consumption is made nearly zero. |
