Current sourcing vs. “pull-down” terminology: In digital outputs, a current-sourcing transistor is equivalent to a pull-up device, not a pull-down. Assess the correctness of calling a current-sourcing transistor a “pull-down” transistor.

Introduction / Context:
In logic outputs, “sourcing” and “sinking” identify the direction of current flow when driving a load. Proper terminology helps avoid wiring mistakes and misinterpretation of fan-out and interfacing requirements.

Given Data / Assumptions:

• A current-sourcing device provides current to the load when output is HIGH (typical of a pull-up path).
• A current-sinking device draws current from the load to ground when output is LOW (typical of a pull-down path).
• We consider standard TTL/CMOS totem-pole or complementary output stages.

Concept / Approach:
By definition, “pull-up” raises the node toward the positive rail and sources current; “pull-down” lowers the node toward ground and sinks current. Calling a sourcing transistor a “pull-down” reverses the meaning and is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Review standard output stage diagrams: the top transistor is associated with pull-up (sourcing), the bottom with pull-down (sinking).

Why Other Options Are Wrong:

Common Pitfalls:
Mixing up current direction conventions; assuming LED wiring polarity changes sourcing/sinking meaning—it does not.

Final Answer:
Incorrect