| 摘要 |
PURPOSE:To prevent transient time from being extended by impedance non- coincidence by constituting the output transistor of a buffer circuit so as to perform a source follower operation. CONSTITUTION:When outputting 'H', a signal at 'H' boosted to an SVcc is impressed to the gate of a Q1 by a driving circuit 1(12). On the other hand, 'H' is impressed to the gate of a Q2 by a driving circuit 2(13). As a result, the Q1 is turned on, the Q2 is turned off, and 'H' is outputted from an output circuit 11. At such a time, a current flows in the order of the Vcc, drain D of the Q1, source S of the Q1, bus line 4, terminating resistor 6 and Vtt, and the Q1 performs the source follower operation. When outputting 'L', a signal at 'L' is impressed to the gate of the Q1 by the driving circuit 1(12). On the other hand, a signal at 'L' voltage-dropped to a Vbb lower than the Vss is impressed from the driving circuit 2(13) to the gate of the Q2. Thus, the Q2 performs the source follower operation. |
