| Figure 1 |
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| In a simplified standard CMOS input (a), the input-to-VDD P+/N clamping diode, D1, creates a live-insertion/removal obstacle because it becomes forward-biased whenever you apply a positive-going signal to an input if you do not apply VDD. For the output circuit of a standard CMOS logic device (b), you typically use a large PMOS pull-up transistor to provide large, high-level output current and large noise margin. |
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