Definition focus – DAC “resolution”: For a digital-to-analog converter, what exactly does the specification “resolution” mean in terms of the smallest change at the output for a one-code increment at the input?

Introduction / Context:
Vendor datasheets list several key DAC/ADC parameters: resolution, accuracy, linearity, monotonicity, and speed. Confusing these terms can lead to poor component choices or unrealistic performance expectations.

Given Data / Assumptions:

• An N-bit DAC with full-scale range VFS (or IFS for current output).
• Ideal behavior assumed for defining terms.
• We want the precise meaning of “resolution.”

Concept / Approach:
Resolution quantifies the granularity of the DAC's output steps. For an ideal N-bit DAC, 1 LSB = VFS / (2^N). A single increment of the digital input changes the output by one LSB. Other specs describe different behaviors: accuracy (overall error), integral nonlinearity (deviation from the ideal straight line), differential nonlinearity (step size error), monotonicity (no step reversals).

Step-by-Step Solution:
Relate the digital code increment (k→k+1) to analog change.Ideal analog step = 1 LSB = VFS / (2^N).Therefore, resolution is the smallest analog output change caused by a 1-LSB input increment.This definition is independent of accuracy or linearity errors.

Verification / Alternative check:
Cross-check with any DAC datasheet block: “Resolution: 12 bits; LSB size: Vref/4096.” This directly defines resolution as the minimum step.

Why Other Options Are Wrong:
Option A describes absolute accuracy.

Option B describes integral linearity error.

Option D is a loose phrasing of monotonicity, not resolution.

Option E refers to update rate (speed), unrelated to step size.

Common Pitfalls:
Equating higher bit count with better accuracy; noise, reference stability, and linearity determine usable resolution (ENOB) in practice.

Final Answer:
It is the smallest analog output change that can occur as a result of an increment in the digital input.