| 摘要 |
<p>Current-mode OR gates useful, for example, in telephone cross-point switch systems. A current-mode OR gate withdraws an output current of predetermined level at its output terminal whenever an input current of sufficient level is applied to one or more of its plurality of input terminals. Each input terminal is connected to the base electrode of a transistor, having its collector electrode connected to the output terminal and having its emitter electrode connected by a resistor to a common terminal. each input current will bias the transistor to which base it is applied, into conduction, to cause its collector current to be withdrawn through the output terminal. The total output current is constrained to the predetermined level by sensing the potential across the resistor and, in response to this potential reaching a predetermined value, clamping each of the input terminals receiving current to prevent further increase of the potential across the resistor.</p> |
