Two ways to build a 4-input AND

You can wire a single 4-input AND gate directly, or cascade three 2-input AND gates: ((A·B)·C)·D. Both compute the identical Boolean function — the difference is entirely in the physical implementation, not the logic.

Fan-in and gate depth

A wide gate has just one stage of delay but requires more transistors internally, driven harder to switch correctly — its fan-in limit. A cascade of 2-input gates has less loading per gate but needs log2(N) stages of delay for N inputs: a 4-input cascade needs 2 gate-delays, an 8-input cascade needs 3. In a timing-critical path, that difference in depth can matter more than the total gate count.

Boolflow's multi-input gates

Boolflow ships AND3/AND4, OR3/OR4, NAND3, NOR3, and XOR3 as single ready-made blocks precisely so you don't have to manually cascade smaller gates when you want the one-stage-delay version — pick whichever matches how you're reasoning about the circuit's timing.

Try it yourself

Build the same 4-input AND function two ways in the circuit editor — one AND4 block, and one cascade of three 2-input AND gates — verify with the Truth Table tool that they agree on every input combination, then count the gate-delay stages between input and output in each version.