Integrated Injection Logic (I2L) vs. TTL fabrication and density: In integrated-circuit logic families, it is often stated that Integrated Injection Logic (I2L) offers very high component density and is simpler to fabricate than Transistor–Transistor Logic (TTL). Evaluate this statement for correctness.

Introduction / Context:
Integrated Injection Logic (I2L) is a bipolar logic family that was developed to achieve extremely high integration density with very low power per gate. When comparing logic families such as I2L and Transistor–Transistor Logic (TTL), two recurring evaluation axes are component density and ease of fabrication. This question asks whether the common claim—“I2L offers high component density and is easier to fabricate than TTL”—is correct.

Given Data / Assumptions:

• I2L uses current injection and simple lateral pnp devices with multi-collector npn transistors to realize logic.
• TTL uses multi-emitter input transistors and a more complex arrangement of bipolar devices per gate.
• We assume mainstream historical bipolar processes intended for high-volume digital logic.

Concept / Approach:
I2L was specifically optimized for gate density and low-power operation by simplifying device structures and leveraging current-injection techniques. The device count per logic function is small, interconnect can be compact, and the fabrication steps are fewer compared with full-feature TTL processes. TTL, while fast and robust, generally requires more complex device structures and interconnect per gate, reducing raw density and making fabrication comparatively more involved.

Step-by-Step Solution:

Verification / Alternative check:
Survey historic bipolar logic overviews: I2L is often cited for ultra-high-density logic and low power, whereas TTL is known for speed and fan-out but with larger gate areas.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing I2L with ECL or TTL in terms of speed; mixing up density (gates per mm^2) with drive strength or noise margins. Also, assuming modern CMOS comparisons apply directly—this question is specifically about I2L vs. TTL.

Final Answer:
Correct