Series identification — 5400 vs. 7400 TTL families: Judge the claim: “The 5400 TTL series logic chips are manufactured to military specifications.”

Introduction / Context:
Classic TTL logic comes in families differentiated by speed, power, and environmental ratings. The 54xx and 74xx numbering historically indicates temperature range and ruggedness. Recognizing these markers helps engineers select suitable parts for industrial or military environments.

Given Data / Assumptions:

• “5400 series” refers to 54xx/54LSxx/54Sxx, etc.
• “Military specifications” means extended temperature range and reliability screening compared with commercial grades.
• General TTL family behavior is assumed; not tied to one manufacturer.

Concept / Approach:
Traditionally, 54xx denotes military/industrial temperature range (e.g., −55 °C to +125 °C) and tighter screening, while 74xx denotes commercial range (e.g., 0 °C to +70 °C or −40 °C to +85 °C in later variants). Functionally similar devices exist across both families, but the 54xx parts are screened for harsher environments, hence the statement is accurate broadly understood.

Step-by-Step Solution:

Verification / Alternative check:
Cross-reference datasheets that list operating temperature ranges and test screens; 54xx families consistently show extended ranges and MIL-style ratings compared to 74xx counterparts.

Why Other Options Are Wrong:

• Incorrect: Contradicts long-standing TTL family conventions.
• Schottky/HSTTL/package only: Logic subfamily or package style is orthogonal to temperature rating conventions.

Common Pitfalls:
Assuming identical performance across numbers; overlooking that newer CMOS logic (e.g., 74HC/74HCT) uses 74xx prefixes but different technologies and temperature grades.

Final Answer:
Correct