| 摘要 |
PURPOSE:To decrease noise caused by a current which flows suddenly by providing a second output buffer whose output is connected to the output of a first output buffer, and an inverter circuit which has its output as an input, and whose output is connected to the gate of the second output buffer. CONSTITUTION:The first output buffer and the second output buffer are constituted of a transistor M11 and M12, and M12 and M14, respectively. In such a case, (gm) of the first output buffers is set in advance to such a magnitude as noise exerts no undesirable influence on an internal circuit, etc., and (gm) of the second output buffer is set in advance to such a magnitude as it compensates an output level, etc., which are deteriorated thereby. In this regard, (gm) of the first output buffer is determined in advance so as to become larger than (gm) of the second output buffer. In such a way, by providing two pieces of output buffers and operating them by shifting its timing, the noise caused by a sudden current which flows through the output buffer can be reduced without deteriorating the output level. |
