| 摘要 |
PURPOSE:To eliminate generation of electric noise by providing plural buffers each different in output connected in parallel, and a control circuit controlling the operating time of the buffers, and operating the buffers in the order of small output sequentially at each prescribed time. CONSTITUTION:Buffers 31, 32 whose outputs differ are provided and a control circuit 4 operates the buffers in the order of small output sequentially at a prescribed time. Since the buffer 31 with a small output is operated at first when the load is small, the rise speed of an input signal current is suppressed to a low value without generating the electric noise. When a large capacity load exists, the buffer 31 with a smaller output is operated at first, but since the output is small, slow reading speed may be caused. However, since the buffer 32 with a larger output is operated succeedingly, the rise of the input signal current is kept nearly the same rising speed as the case with the small capacitive load. |
