Digital IC technology preferences: Bipolar technology is traditionally preferred for which integration scales, while MOS is better for LSI?

Introduction / Context:
Historically, bipolar transistor technologies (e.g., TTL, ECL) offered high speed and strong drive, making them suitable for small- and medium-scale integration (SSI/MSI). Metal-oxide-semiconductor (MOS) technologies excel at very high transistor densities, making them the dominant choice for large-scale integration (LSI/VLSI).

Given Data / Assumptions:

• SSI (small-scale) and MSI (medium-scale) involve relatively few gates per chip.
• LSI/VLSI integrate thousands to millions of transistors.
• We compare typical historical preferences, not niche exceptions.

Concept / Approach:
Bipolar devices switch quickly and drive loads well but consume more power and scale poorly in density compared to MOS. MOSFET processes permit compact, low-power gates suitable for massive integration, the basis of modern microprocessors and memory chips.

Step-by-Step Solution:
Match bipolar strengths (speed/drive) to SSI/MSI.Match MOS strengths (density/low power) to LSI/VLSI.Therefore, choose “SSI, MSI” for bipolar, with MOS better for LSI.

Verification / Alternative check:
The transition from TTL/ECL logic families to CMOS for high-integration ICs in the 1980s–1990s reflects this preference shift.

Why Other Options Are Wrong:
“MSI, LSI” mixes scales and contradicts the density advantage of MOS. “SSI, LSI” splits scales inconsistently. “ECL, DTL” lists families, not integration scales.

Common Pitfalls:
Assuming “faster” always means “better”; for large chips, power and density dominate over raw switching speed.

Final Answer:
SSI, MSI