Work out gate propagation delay instantly with clear inputs, formula shown and shareable results.
Gate delay is an intrinsic term plus a load term of 0.69 x Rdrive x Cload. FO4 — an inverter driving four copies of itself — is the standard technology speed metric, and a rule of thumb is that a process's FO4 delay in picoseconds is roughly 0.5 times the node in nanometres.
Gate delay
tpd = t_intrinsic + 0.69 x Rdrive x Cload; FO4 uses a load of four identical gates
It is self-scaling and technology independent: the load is defined relative to the gate itself, so FO4 delays compare processes fairly.
Reduce fanout, upsize the driver (lower Rdrive), or insert a buffer. Upsizing helps only until the larger gate's own input capacitance loads the previous stage.