In data conversion terminology, a DAC (digital-to-analog converter) performs which function?
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Aan analog signal into digital data
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Bdigital data into an analog signal
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Cdigital data into an amplified signal
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Dnone of the above
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Eanalog signal into a frequency spectrum
Answer
Correct Answer: digital data into an analog signal
Explanation
Introduction / Context:Mixed-signal systems require converting between digital codes and real-world analog signals. A digital-to-analog converter (DAC) is essential in audio playback, instrumentation, motor control, and waveform generation.
Given Data / Assumptions:
- DAC receives binary (or coded) digital words.
- Output should be a corresponding analog level (voltage or current).
- No amplification is implied unless specified; conversion is the core function.
Concept / Approach:A DAC maps a digital code to a proportional analog quantity. For an n-bit DAC with reference Vref, the smallest analog step is typically Vref / (2^n). The output may be a staircase that can be smoothed by a reconstruction filter.
Step-by-Step Solution:Identify device → DAC.Define action → digital code → analog magnitude (voltage or current).Exclude unrelated actions such as A/D or amplification.
Verification / Alternative check:Audio DACs convert 16-bit or 24-bit PCM data into line-level analog voltages for speakers after buffering and filtering, confirming the role.
Why Other Options Are Wrong:Analog-to-digital is ADC, not DAC.Amplification may follow a DAC but is not inherent to conversion.Frequency spectrum conversion is unrelated.
Common Pitfalls:Assuming a DAC inherently amplifies or filters. Those are separate stages (op-amp buffer, active filter).
Final Answer:digital data into an analog signal