Difficulty: Easy
Correct Answer: Bipolar
Explanation:
Introduction / Context:Some applications require signals that swing around a zero reference, such as audio waveforms or servo commands. DACs designed for such use must support both positive and negative outputs. The correct terminology distinguishes these from unipolar-only devices that output one polarity relative to ground.
Given Data / Assumptions:
Concept / Approach:A bipolar DAC or bipolar output configuration can produce both positive and negative voltages with respect to ground (or another reference), typically using dual supplies or level-shifting around a midscale reference. Unipolar DACs output from zero to a positive full-scale (or zero to a negative full-scale) and cannot cross zero without added analog conditioning.
Step-by-Step Solution:
Identify requirement: output must cross zero and swing both ways.Match term: “bipolar” specifically denotes two polarities.Select the answer “Bipolar.”Verification / Alternative check:Datasheets specify ranges like “±10 V bipolar” versus “0 to 10 V unipolar,” confirming the terminology used in practice.
Why Other Options Are Wrong:
Tristate: Refers to digital output high-impedance states, not analog polarity.Double: Not a standard DAC range descriptor.Unilateral: Not a conventional term for DAC ranges; unipolar is the typical counterpart to bipolar.Common Pitfalls:Assuming any DAC can be made bipolar without considering headroom, references, and amplifier rails.
Final Answer:Bipolar
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