MOSFET

Which expression roughly represents the delay of a CMOS logic gate? (C: load capacitance, V: supply voltage, I: drive current)

  1. AC × V ÷ I
  2. BI ÷ (C × V)
  3. CC × V × I
Show answer and explanation

Answer: A. C × V ÷ I

Gate delay can be viewed as the time needed to charge or discharge the load capacitance C to the supply voltage V, roughly CV/I. Reducing load capacitance and increasing drive current lead to higher speed. Lowering the voltage also reduces the current, so delay tends to increase.

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