6.15 Accoring to Section 5.2.5 for the TSMC 180 nm process, a P/N ratio of 3.6:1 gives
equal rising and falling delays of 84 ps, while a P/N ratio of 1.4:1 gives the mini-
mum average delay of 73 ps, a 13% improvement (not to mention the savings in
power and area). Recall that the minima is very flat; a ratio between 1.2:1 and 1.7:1
all produce a 73 ps average delay.
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