| 摘要 |
PURPOSE:To obtain a tri-state circuit which is reduced in occupation area by decreasing the number of MOS transistors. CONSTITUTION:when an OE signal is at high level, a Q3P is off and the source side of a Q2 P rises to high level; and a Q3N turns off and the source side of a Q1N falls to low level. When a DATA signal is held at low level, the Q1P and Q2P turn on and the Q1N and Q2N turn off, so an output Y falls to low level. Further, when the DATA signal is raised to high level, the Q1P and Q2P turn off and the Q1N and Q2N turn on, so the output Y rises to high level. When the OE signal is held at low level, the Q3P and Q3N both turn on. The gate potential of a Q4P is high in level and the gate potential of a Q4N is low; and the both turn off, so the output Y has high impedance. |
