AD/DA conversion

In a time-interleaved ADC that alternates between several ADCs, what problem is caused by mismatches in offset, gain and timing between the individual ADCs?

  1. AUnwanted spurs appear at specific frequencies related to the sampling frequency
  2. BThe input range automatically widens
  3. CMissing codes are always eliminated
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Answer: A. Unwanted spurs appear at specific frequencies related to the sampling frequency

If the interleaved ADCs differ slightly, the differences become an error that repeats with the switching period, producing spurs at positions related to the sampling frequency divided by the number of ADCs. High-performance interleaved ADCs remove these mismatches with digital calibration.

  • A. Correct. Spurs appear related to the switching period.
  • B. Mismatches do not widen the input range.
  • C. Mismatches do not eliminate missing codes.
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More AD/DA conversion questions

  1. Which correctly describes the "offset binary" code used in ADCs that handle both positive and negative voltages?
  2. How many output levels can an 8-bit AD converter represent?
  3. What sampling frequency is needed to sample an analog signal containing components up to 20 kHz without aliasing?
  4. Which is a characteristic of a flash AD converter?
  5. Which correctly describes the operation of a successive-approximation (SAR) AD converter?