| 摘要 |
PURPOSE:To curtail a useless power consumption at the time of stand-by by setting the output stage of an inverter constitution of an operational amplifier to a high impedance state, and detaching it exactly from an output terminal. CONSTITUTION:When a control input terminal 1 is in an H level, a PMOSFET (PMF) 9 is turned off an an nMOSFET (nMF) 10 is turned on, the gates of nMFs 11-13 of output of a current mirror circuit are changed to an L level, and to a bias circuit 30, a differential amplifier circuit 31, and a first output circuit 32, a current comes not to flow. Subsequently, an nMF 19 is turned on, an H level is added to a gate of an nMF 21, the nMF 21 is turned on, L is added to the gate of an nMF 29, and the nMF 29 is turned off. Also, in an OR circuit 34, an nMF 22 is turned off an an nMF 23 is turned on, the gate of an nMF 26 becomes L and turned on, and the gate of an nMF 28 becomes H and turned off. In such a way, an output stage 35 of an inverter constitution becomes a high impedance, and waste of power at the time of stand-by is prevented.
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