| 摘要 |
An emitter-coupled logic (ECL) circuit having a pull-down resistor and including a breakdown protecting structure. Such breakdown occurs in an input transistor for receiving input data when an excess reverse voltage is applied across the emitter and base of the input transistor. The breakdown protection structure preferably includes a constant-voltage regulating device which can always clamp the level of a reference voltage VBB to a suitable level higher than a low voltage VEE of a power source by the value of a constant voltage. The reference voltage VBB is usually applied to the base of another transistor which should be coupled, at respective emitters, with the input transistor by the representative emitters. |
