A data logger samples 8 channels, each at 5 kHz with 12-bit resolution. Find the raw data rate Rb in kbit/s.
Data acquisition & sampling worksheet with answers
A sensor signal contains frequencies up to 0.5 kHz. Find the minimum sampling rate fs,min that captures it without aliasing.
A 10-bit ADC with an input range of 0 to 2.5 V truncates: its output code is ⌊Vin/LSB⌋ with 1 LSB = VFSR/2ᴺ. Find the decimal output code D for an input of 0.961 V.
A 3.2 kHz sine wave is sampled at 2 kHz without an anti-aliasing filter. At which frequency fa does it appear in the samples? Give it in Hz.
A 2.4 kHz square wave is sampled at 20 kHz with no anti-aliasing filter. A square wave contains the odd harmonics 3f₁, 5f₁, 7f₁, … At which frequency fa does its harmonic 7f₁ appear in the sampled data? Give it in kHz.
An audio measurement needs an ideal signal-to-quantisation-noise ratio of at least 40 dB for a full-scale sine wave. Find the smallest number of ADC bits N.
Answer key
- 1. Rb = 480 kbit/s
- 2. fs,min = 1 kHz
- 3. D = 393
- 4. fa = 800 Hz
- 5. fa = 3.2 kHz
- 6. N = 7
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