Logic-level parameters across families: Is it correct that digital IC families specify four logic-level parameters: VIL, VIH, VOL, and VOH?

Introduction / Context:Understanding logic-level thresholds and output drive limits is fundamental for interfacing between IC families. Standard datasheet parameters define input recognition levels and guaranteed output levels for logic 0 and logic 1. This question checks familiarity with those four canonical parameters.

Given Data / Assumptions:

• VIL and VIH are input-level thresholds defining recognized LOW and HIGH ranges.
• VOL and VOH are guaranteed output voltage levels for LOW and HIGH outputs under specified load.
• Applies to TTL, CMOS, and other families with different numeric values.

Concept / Approach:Datasheets nearly always present VIL, VIH, VOL, and VOH. Designers ensure margin by comparing an output's VOL/VOH against the next stage's VIL/VIH. While the numeric values differ (for example, TTL vs. CMOS vs. LVCMOS), the categories remain consistent and enable safe logic-level interfacing and noise-margin analysis.

Step-by-Step Solution:

Verification / Alternative check:Any standard datasheet for 74-series TTL or 4000-series CMOS lists these parameters, confirming the statement.

Why Other Options Are Wrong:

Common Pitfalls:Ignoring load conditions that affect VOL/VOH; always check the test current and supply when comparing levels.

Final Answer:Correct