D/A converter fundamentals — definition of resolution Which statement correctly defines the resolution of a digital-to-analog (D/A) converter?
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AIt is the reciprocal of the number of discrete steps in the D/A output.
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BIt is the comparison between actual output and expected output.
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CIt is the deviation between the ideal straight-line output and the actual output.
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DIt is the ability to resolve between forward and reverse steps across the range.
Answer
Correct Answer: It is the reciprocal of the number of discrete steps in the D/A output.
Explanation
Introduction / Context:Resolution indicates the smallest analog change a D/A converter can produce for a one-LSB digital change. It is fundamental when matching a converter to sensor accuracy and control requirements.
Given Data / Assumptions:
- N-bit DAC has 2^N discrete output steps across full-scale range.
- Resolution is typically expressed as a fraction (1/2^N of full scale) or as a percentage.
Concept / Approach:For an ideal N-bit DAC, the minimum output increment (1 LSB) equals full_scale / 2^N. As a fraction of full scale, resolution = 1 / 2^N, which is the reciprocal of the number of steps. (Sometimes expressed in volts: V_LSB = V_FS / 2^N.)
Step-by-Step Solution:Number of steps = 2^N.Resolution (fraction of full scale) = 1 / 2^N.Hence, it is the reciprocal of the number of discrete steps.
Verification / Alternative check:Example: 10-bit DAC → 1024 steps → resolution ≈ 0.0977% of full scale per LSB, matching the reciprocal definition.
Why Other Options Are Wrong:
- Comparison between actual and expected output defines accuracy.
- Deviation from ideal straight line defines linearity error.
- Forward/reverse step resolving addresses monotonicity/hysteresis, not resolution.
Common Pitfalls:
- Confusing resolution with accuracy or linearity.
- Forgetting that resolution sets granularity; accuracy tells how close outputs are to ideal.
Final Answer:It is the reciprocal of the number of discrete steps in the D/A output.