Difficulty: Easy
Correct Answer: 2–5V
Explanation:
Introduction:Digital logic families define voltage thresholds for interpreting signals as Logic 0 (LOW) or Logic 1 (HIGH). Knowing these ranges ensures reliable interfacing and noise immunity.
Given Data / Assumptions:
Concept / Approach:Classic TTL specifies VIL(max) around 0.8 V and VIH(min) around 2.0 V, with VCC near 5 V. Thus, valid HIGH levels are typically any voltage from roughly 2.0 V up to VCC (about 5 V).
Step-by-Step Solution:
Identify VIL(max) = 0.8 V (given).Typical VIH(min) for TTL ≈ 2.0 V.Acceptable HIGH range ≈ 2.0 V to 5.0 V.Match with provided options: 2–5V.Verification / Alternative check:CMOS families at 5 V often use fractions of VCC, but TTL-compatibility commonly accepts ≥ 2.0 V as HIGH in mixed systems; 2–5V remains the broadly correct range here.
Why Other Options Are Wrong:
Common Pitfalls:Assuming all families use identical thresholds; always consult the specific datasheet. However, the 2–5 V convention remains a widely taught baseline for TTL levels.
Final Answer:2–5V
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