| 摘要 |
PURPOSE:To shorten a period of flowing a current from the power supply of a schmitt circuit to reduce power consumption considerably by installing a 1st switch between the input side of the schmitt circuit and the I/O terminal thereof, and installing a 2nd switch between the input side of the schmitt circuit and the input side of an output buffer circuit. CONSTITUTION:Between the input side of a schmitt circuit 6 consisting of CMOS and a terminal 1 for a combined use of input/output, the 1st switch 4 is connected, and the 2nd switch 5 between the input side of an output buffer circuit 2 connected to the input/output terminal 1 and the input side of the schmitt circuit 6. When a signal to be externally output is applied to the output buffer circuit 2, the 1st switch 4 is turned off, while the 2nd switch is turned on. Further, when a signal to be applied to the output buffer circuit 2 is applied to the schmitt circuit 6, the level of the signal applied to the schmitt circuit 6 immediately changes. In such a way, the schmitt circuit 6 carries out high speed switching, thereby considerably reducing power consumption in the schmitt circuit 6. |
