14
8. SQUARE WAVE - LOW LEVEL - NOISY
Demo: with:
DOX2025
DOX2040
DOX2100
DOX2xxxB
Test Signal
n°8 : Square wave, low level, noisy
Nature
1 square wave of very low amplitude and very noisy
Specs
5 mV < Vpp < 30 mV (depending on filtering) - F ≈ 1 kHz
Oscilloscope Settings
200 or 500 µs/div. - MAIN = 2.5 or 5 mV/div.
Trigger
on MAIN, 50 % of Vpp
Modes
nothing at first, then 100 kHz low-pass filtering
Objectives
Triggering and display for a noisy signal
Using the Digital filters
a) Adjust the oscilloscope so as to display the signal approximately.
Attention, with this type of signal, “Autoset” operation may be aleatory.
The noisy signal is of low amplitude.
b) The use of a 100 kHz digital low-pass filter makes it possible to analyse the signal without the noise.