DAC resolution dependency: In a digital-to-analog converter, the analog output step size (smallest output change) is primarily determined by the number of input bits, with full-scale range also influencing absolute step magnitude. Evaluate this statement.

Introduction / Context:
Resolution tells how finely a DAC can represent analog values given digital codes. Designers often size the number of bits to meet an application’s dynamic-range and quantization-noise targets, then choose a reference to set absolute volt levels.

Given Data / Assumptions:

• N-bit DAC with reference Vref and full-scale range dependent on architecture.
• Ideal LSB size = full_scale / (2^N − 1) (often approximated as VFS / 2^N).
• Non-idealities (INL/DNL, noise) do not change the fundamental dependency.

Concept / Approach:
Increasing bit count halves the LSB size each added bit, improving resolution exponentially with N. While Vref sets the absolute voltage per step, the primary driver of how many distinct analog levels exist is the number of bits (2^N codes).

Step-by-Step Solution:
1) Distinct codes = 2^N.2) Ideal step size ≈ VFS / 2^N.3) Add one bit → step size halves.4) Therefore, resolution scales principally with N.

Verification / Alternative check:
Compare a 10-bit vs 12-bit DAC at same Vref; LSB shrinks by factor 4, confirming N is the prime factor.

Why Other Options Are Wrong:
“Incorrect” ignores the 2^N relationship. Constraints about zero Vref or thermometer coding do not alter the bit-driven code count.

Common Pitfalls:
Confusing resolution (LSB size) with accuracy or linearity; non-idealities limit effective resolution but not the theoretical 2^N levels.

Final Answer:
Correct