| 摘要 |
A circuit for predriving a signal conductor includes a logic circuit/level sensing control mechanism that prevents the simultaneous condition of switching devices through which the signal conductor is coupled to respective predrive voltage sources, thereby avoiding the establishment of a current path from a power supply source to ground. First and second controlled current flow paths are provided by way of first and second switching transistor circuits, that are coupled between first and second voltage reference sources, corresponding to first and second logic levels, respectively, and the signal conductor to be driven. To predrive the conductor, the current flow path through one of the transistor circuits is gated on, while the current flow path through the other transistor circuit is interrupted. At the same time the flow of current between the other voltage source and the signal conductor is inhibited, as the signal conductor is brought to an intermediate voltage level. The voltage level on the signal conductor is sensed continuously. Upon the voltage level of the signal conductor being brought to the intermediate voltage level, the current flow paths through both transistor circuits are interrupted, so that an unwanted current path through the predrive circuit cannot be established.
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