Introductory concepts - Practical Biomedical Signal Analysis Using MATLAB - page 6

FIGURE 1.2: Illustration of the aliasing effect. Samples taken every 0.1 s from
a 9 Hz sinusoid (black) are exactly the same as these taken from the 1 Hz sinusoid
(gray).

FIGURE 1.3: Illustration of the quantization error for a 3 bit ADC. The digitized
representation (black line) of the continuous sinusoid (gray line). The range of 2 [V]
is divided into 8 levels. The sampled signal values (black dots) are rounded to the
nearest ADC level.

so that ± 200 μV covers the full range of a 12 bit ADC. This range is divided into bins

2 12 of 400 / = 400 / 4096 ≈ 0 . 1 μV . It means that we measure the amplitude of the

signal with precession ± 0 . 05 μV .