| 摘要 |
PURPOSE:To use one circuit device for plural kinds of output buffer circuits by constituting plural kinds of output buffer circuits composing of plural circuits while using a part of circuit components in common and providing a control element selecting the said circuits. CONSTITUTION:In bringing a high impedance control terminal 24 to an H level and an open drain control terminal 25 to an L level, the level of an output signal terminal 33 depends on a voltage level at a terminal 26 and the circuit acts like a push-pull circuit. In bringing the level of the terminal 24 to an L level in this state, a P-channel FET 32 and an N-channel FET 34 are both cut off, the terminal 33 reaches a high impedance state and the circuit acts like a tri-state circuit. Then in bringing the terminal 24 to an L level and the terminal 25 to an H level, the FET 32 is cut off, the FET 34 is controlled by the input signal terminal 26 and the circuit acts like an open drain circuit. Thus, one CMOS IC is used for three kinds of output buffer circuits. |
