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Alternating Buffers and Pass Transistors
to go faster!

Consider driving a series of wires (no fanout)...

  1. only pass transistors
    • quadratic delay
    • faster for 2-3 hops
  2. only buffers
    • linear delay
    • faster for 4++ hops
  3. alternate them
    • buffer, pass, buffer, pass, ...
    • linear delay
    • pass transistor => lowers slope => faster
  4. generally: buffer/N-pass
    • buffer followed by N pass transistors

A. All switches same size.