AD/DA conversion

Which is the approximate formula for the signal-to-noise ratio (SNR) of an ideal N-bit AD converter, set by quantization noise? (For a full-scale sine-wave input)

  1. A6.02N + 1.76 dB
  2. B3N dB
  3. C20N dB
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Answer: A. 6.02N + 1.76 dB

For an ideal ADC, SNR ≈ 6.02N + 1.76 dB, improving by about 6 dB for each additional bit. For example, 12 bits give about 74 dB. Real ADCs fall short of this because of thermal noise, distortion and other factors.

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More AD/DA conversion questions

  1. Which is a characteristic of the dual-slope AD converter often used in digital multimeters?
  2. Which correctly describes the differential nonlinearity (DNL) of an AD converter?
  3. What is the AD converter defect called in which a certain output code never appears no matter how the input changes?
  4. Which is a characteristic of the current-steering architecture often used in high-speed DA converters?
  5. Which metric converts the performance of a real AD converter, including noise and distortion, into the bit count of an ideal ADC?