Device tolerances in thyristors Two thyristors of the same rating and specification are tested. What can be said about their on-state voltage drops and forward blocking characteristics?

Introduction / Context:
Even with identical part numbers, semiconductor devices exhibit parameter spread due to manufacturing tolerances. Understanding this spread is critical when paralleling or series-connecting devices and when estimating losses.

Given Data / Assumptions:

• Same part number and data-sheet limits.
• Normal production tolerances; devices not bin-sorted.
• Measurements under same test conditions.

Concept / Approach:

Data sheets specify ranges or typical values (with max/min limits) for forward drop, leakage, and blocking capability. Two nominally identical devices can have slightly different forward drops and leakage due to doping variations, die size, and packaging. Hence equal or different values are both possible within specified limits.

Step-by-Step Solution:

Verification / Alternative check:

Manufacturers often provide statistical distributions. Engineering practice uses equalizing resistors/capacitors for series/parallel operation to mitigate mismatch.

Why Other Options Are Wrong:

Options asserting “always equal” or “always different” are too absolute and conflict with real-world tolerance bands.

Common Pitfalls:

Assuming part number implies exact equality; overlooking temperature dependence that can widen measured differences.

Final Answer:

They may be equal or different in on-state drop and in forward-blocking characteristics for the same current