| 摘要 |
An output buffer for reducing the signal noise associated with the switching between logic high and logic low electrical. Signals includes a first clamping circuit linked to the pull-up output transistor of the buffer, and a second clamping circuit linked to the pull-down output transistor of the buffer. The buffer may include both clamping circuits or either the first or second clamping circuit alone, dependent upon signal shaping interests. Each of the clamping circuits includes a selectable delay stage coupled to the buffer's input, a current regulator controlled by the delay stage, and a clamping device that is coupled to the control node of the output transistor. When the current regulator is conducting, the control node of the output transistor is clamped at a potential near its threshold turn-on. As a result, when the clamping circuit is turned off, the output transistor experiences a soft turn-on, thereby reducing signal bounce and the associated noise.
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