Splitter & Confluence Lab

Splitter: one SFQ pulse → two clean copies (fanout is not free). Confluence: two on-ramps → one lane; staggered arrivals OK, nearly simultaneous → hazard.

Extra delay on branch B (skew) 0·τ

Target leaves N (tree depth) 8

d ≥ ⌈log₂ 8⌉ = 3 · full binary tree uses N−1 = 7 splitters

Copies out

Skew |tA−tB|

0·τ

Tree depth

Splitters (N−1)

One in → two out; unmatched B delay = leaf skew

Match branches (skew → 0) for clocks. Depth formula counts splitter levels; JTL stubs are extra.

Arrival offset B − A (·τ) +3·τ

|offset|

3·τ

Safe window

≥ 2·τ

Merge result

—

Rule

stagger

Two on-ramps → one highway — cartoon hazard window (illustrative)

Public rule: exclusivity or separation first; confluence second — not a CMOS wired-OR. Hazard window here is pedagogical (±1·τ), not a PDK number.