Two thyristors of the same rating and datasheet specifications are used. What can be said about their turn-on and turn-off times in practice?

Introduction / Context:
Even when power devices carry the same ratings and come from the same datasheet, real components exhibit manufacturing tolerances. In series/parallel connections or matched legs of converters, recognizing spread in dynamic parameters is important for equalizing networks and safe sharing.

Given Data / Assumptions:

• Two SCRs of same type number and specified ratings.
• Turn-on and turn-off times are measured dynamic parameters with tolerances.
• Operating conditions (temperature, gate drive, current) may differ slightly in-circuit.

Concept / Approach:

Datasheets specify typical/maximum values and ranges; individual units can vary. Therefore, equal dynamic times are not guaranteed, though they can be close. Design must accommodate mismatch via snubbers, equalizing components, and gate drive margins.

Step-by-Step Reasoning:

Verification / Alternative check:

Manufacturers list statistical spreads; production tests show unit-to-unit variance even within the same lot.

Why Other Options Are Wrong:

• Will have equal... too strong; ignores tolerances.
• Will have unequal... also too strong; sometimes they are close enough to be effectively equal.
• Always identical... unrealistic in power semiconductor practice.

Common Pitfalls:

• Assuming identical part numbers imply identical dynamic performance.
• Neglecting equalizing networks for series/parallel SCRs.

Final Answer:

may have equal or unequal turn on and turn off periods