Can totem-pole outputs be tied together? Evaluate the safe interconnection of totem-pole (push–pull) logic outputs and select the best explanation for whether they may be directly paralleled.

Introduction / Context:Totem-pole (push–pull) outputs actively drive both HIGH and LOW using complementary transistors. They provide fast edges but are not intended for wired-OR/wired-AND interconnection. Understanding why prevents device damage and bus contention in digital systems.

Given Data / Assumptions:

• Each totem-pole output sources current when HIGH and sinks current when LOW.
• No inherent isolation exists between tied outputs.
• Logic states can differ momentarily due to skew or permanently due to differing logic.

Concept / Approach:If two totem-pole outputs are directly tied and ever drive opposite states, one device will attempt to source while the other sinks, creating a near-short between supply rails through the output transistors. This can cause excessive current, heating, logic errors, or catastrophic failure. Open-collector/open-drain outputs, by contrast, are designed for wired-OR with a shared pull-up.

Step-by-Step Solution:

Verification / Alternative check:Family datasheets and application notes forbid paralleling totem-pole outputs. Bus architectures use tri-state (three-state) outputs with arbitration instead.

Why Other Options Are Wrong:

Common Pitfalls:Assuming paralleling works because it does for power supplies; digital outputs are not current-sharing devices and lack ballast for equalization.

Final Answer:cannot, together, if the outputs are in opposite states excessively high currents can damage one or both devices