Triggering behavior of multivibrators: The statement “Multivibrators must be level-triggered” should be classified as which of the following?

Introduction / Context:
Multivibrators are fundamental timing circuits: astable (free-running oscillator), monostable (one-shot), and bistable (flip-flop). Their triggering behavior varies by type and implementation. Confusing level-triggered with edge-triggered operation leads to misapplied inputs and unreliable timing in designs and tests.

Given Data / Assumptions:

• Different multivibrator types exist with different triggering styles.
• Edge-triggered and level-sensitive designs are both common.
• IC implementations (e.g., 74xx one-shots, flip-flops) specify required trigger characteristics.
• Noise immunity/Schmitt action can alter sensitivity to levels or edges.

Concept / Approach:
The blanket claim that multivibrators “must be level-triggered” is incorrect. Monostables are often edge-triggered (responding to a rising or falling edge). Bistables (flip-flops) can be edge-triggered (master–slave, edge-triggered D) or level-sensitive (latches). Astables require no external trigger—they self-oscillate. Thus, multivibrators do not universally require level triggering; the correct trigger model depends on the specific circuit topology and device.

Step-by-Step Solution:

Verification / Alternative check:
Datasheets for common one-shots (e.g., 74121/74123) specify edge-trigger inputs. Edge-triggered D flip-flops (e.g., 7474, 74HC74) explicitly require clock edges; latches (e.g., 74HC373) are level-sensitive. This diversity disproves the universal claim.

Why Other Options Are Wrong:

Common Pitfalls:
Driving an edge-triggered input with a slow ramp (causes multiple triggers or none); forgetting to debounce level-sensitive triggers; assuming all FFs behave like latches.

Final Answer:
Incorrect