TTL supply requirement — fact check: Transistor–Transistor Logic (TTL) devices require a regulated supply near 5 V (nominal), not 8.0 V. Evaluate the statement: “TTL requires a constant supply voltage of 8.0 V.”

Introduction / Context:
Correct supply voltage knowledge is essential to avoid damaging logic devices. TTL families (74xx, 74LS, 74ALS, etc.) have long standardized on a 5 V supply, with defined noise margins and logic thresholds around that nominal value.

Given Data / Assumptions:

• Standard TTL operates at VCC ≈ 5 V (typical 4.75–5.25 V tolerance for many families).
• Absolute maximum ratings prohibit substantially higher continuous supply voltages.
• Some CMOS families (e.g., 4000B) tolerate wider ranges, but that is not TTL.

Concept / Approach:
The proposed 8.0 V requirement is incompatible with TTL design. Transistor biasing, input thresholds, and output levels are engineered for 5 V rails. Applying 8 V risks exceeding maximum ratings and destroying the device. Specialized translators or regulator stages are used when interfacing to other voltages.

Step-by-Step Solution:
Identify family: TTL → nominal 5 V.Check datasheet ranges: typically around 4.75–5.25 V for standard parts.Compare to claim: 8.0 V is far outside operating limits.Therefore the statement is false.

Verification / Alternative check:
Datasheets for 74LS00, 74ALS00, etc., specify VCC = 5 V nominal. None require 8 V.

Why Other Options Are Wrong:
Open-collector outputs do not change core supply needs. “Military-grade” or temperature ratings do not redefine VCC to 8 V.

Common Pitfalls:
Confusing TTL with certain analog or CMOS families; misreading absolute maxima as operating points.

Final Answer:
Incorrect