JK flip-flop 7476 timing comparison: Are the LOW-to-HIGH and HIGH-to-LOW propagation delays (clock to output) the same, and if not, what typical values apply?

Introduction / Context:
Propagation delay in TTL devices often differs for rising and falling transitions due to internal transistor structures and output stages (e.g., totem-pole behavior). The 7476 JK flip-flop typically has different delays for LOW-to-HIGH (tPLH) and HIGH-to-LOW (tPHL) transitions.

Given Data / Assumptions:

• Device: 7476 JK flip-flop.
• We compare clock-to-Q delays for both edges.
• Representative typical values are sought.

Concept / Approach:
Datasheets list separate tPLH and tPHL because device paths and transistor saturation differ per transition. Designers must consider the larger of the two when budgeting timing to avoid overestimating maximum system frequency.

Step-by-Step Solution:
Identify both delays: tPLH (Q rising), tPHL (Q falling).Typical 7476 values show tPHL > tPLH.Adopt tPLH ≈ 25 ns and tPHL ≈ 40 ns as representative.

Verification / Alternative check:
Cross-check multiple vendor datasheets; while absolute numbers vary, the asymmetry (falling often slower) remains consistent.

Why Other Options Are Wrong:
“Yes” and “identical” contradict typical TTL behavior.Swapped numbers or alternative pairings don’t reflect common 7476 figures.

Common Pitfalls:
Using only a single “tpd” value in timing closure; always use the worst case between the two directions for safe margins.

Final Answer:
no, tPLH = 25 ns, tPHL = 40 ns