A 10-bit ADC that rounds to the nearest code has an input range of 0 to 2.5 V. With 1 LSB = VFSR/2ᴺ, find the largest quantisation error eq,max in mV.
Data acquisition & sampling worksheet with answers
A data logger samples 3 channels, each at 48 kHz with 24-bit resolution. Find the raw data rate Rb in kbit/s.
A 1.35 kHz sine wave is sampled at 1 kHz without an anti-aliasing filter. At which frequency fa does it appear in the samples? Give it in Hz.
A recorder samples 2 channels at 5 kHz each with a 24-bit ADC. Each sample is stored in whole bytes. Find the memory M needed for a 1 min recording, in MB (1 MB = 10⁶ bytes).
A 12-bit ADC streams every sample over a UART at 115200 baud, format 8E1 (start bit, 8 data bits, even parity, 1 stop bit). Each sample is sent as 2 whole byte(s) and the link is busy all the time. Find the highest signal frequency fmax that can be sampled without aliasing, in Hz.
An 8 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 3f₁ appear in the sampled data? Give it in kHz.
Answer key
- 1. eq,max = 1.221 mV
- 2. Rb = 3456 kbit/s
- 3. fa = 350 Hz
- 4. M = 1.8 MB
- 5. fmax = 2618 Hz
- 6. fa = 4 kHz
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