| 摘要 |
PURPOSE:To improve the effect of the charge and the discharge of a load capacity by a PNP transistor by making the amplitude of a signal impressed on the base of the PNP transistor for active pull-down larger than the amplitude of the signal impressed on the base of an NPN emitter follower transistor. CONSTITUTION:The transistors 11 and 12, a constant-current source 13 and resistances 14-17 constitutes a current switch and the resistance 17, the transistors 18 and 19 and the resistance 22 constitutes a level shift circuit. By making the amplitude of the signal inputted in the base of the PNP transistor 21 for the active pull-down larger than the amplitude of the signal inputted in the base of the NPN emitter follower transistor 20, the velocity that the current of the transistor decreases is accelerated when the output VOUT rises and the veloiity that the current increases is accelerated when the output VOUT breaks. Thus, the effect of the charge and discharge of the load capacity 23 by the PNP transistor can be raised and a switching velocity can be made higher.
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