Oscilloscope Probe

This circuit is a passive osciloscope probe that have a divide ratio of 10 to 1 and cause no distortion in the signal of interest. That means than the input signal is getting 10 times smaller in magnitude in all frequency range and with no phase shift. In order to see that function run the simulation and try to change the frequency of the input signal rapidly or slowly whilst observing the output signal. You will notice no distortion (note that at very high frequencies the simulation show small deviations but I believe is a simulation error). Also if you run an AC analysis you will notice that the transfer function is a straight line both in magnitude and phase. In reality though that is not the case. The circuit that we investigate interact with the probe circuit and that interaction can cause distortion to the signal of interest. For example oscillations.

published 10 years ago