In standard TTL (transistor–transistor logic) families, the majority of logic gates employ a totem-pole (push–pull) output stage to provide low output impedance, fast edges, and active drive for both logic HIGH and logic LOW. Evaluate this statement.

Introduction / Context:
Totem-pole (also called push–pull) outputs are a hallmark of most standard TTL logic gates. This arrangement actively drives the output HIGH and LOW using a pair of transistors stacked like a totem pole, delivering sharper transitions and better fan-out than passive pull-ups.

Given Data / Assumptions:

• The statement claims most TTL gates use a totem-pole output.
• We are talking about mainstream 74xx TTL families, not special variants.
• Open-collector and tri-state outputs exist but are options, not the default for most basic gates.

Concept / Approach:
A totem-pole output uses an upper transistor (source current when HIGH) and a lower transistor (sink current when LOW). This design reduces output impedance, shortens rise/fall times, and improves speed compared to resistor pull-ups. Classic 74, 74LS, and 74S families commonly use totem-pole outputs for standard gates like AND, OR, NAND, NOR, and inverters.

Step-by-Step Solution:
Identify the common default TTL output stage → totem-pole.Note special cases (open-collector, tri-state) are variants for bus-ORing or bus sharing.Compare prevalence: standard gates ship with totem-pole by default.Conclude the statement is correct for most TTL gates.

Verification / Alternative check:
Datasheets for 74LS00, 74LS04, etc., show push–pull output stages with specified I_OH (source) and I_OL (sink), confirming the default totem-pole configuration.

Why Other Options Are Wrong:
Open-collector TTL is a special variant, not “most.” Tri-state outputs support bus sharing but are not the default for basic gates. “Schottky CMOS” is a mismatched technology label.

Common Pitfalls:
Assuming wired-OR capability on totem-pole outputs; that is unsafe unless using open-collector/tri-state with proper resistors and control.

Final Answer:
Correct