Question 1:
Considering the typical probe schematic presented in Figure 7, determine how the adjustable capacitor value can be computed to compensate the frequency response.
Answer 1:
In order to obtain a proper adjustment the following relationship must be met:
Where we denote:
R1 = Probe resistance
C1 = Probe parasitic capacitance
R2 = Scope input capacitance
C2 = capacitance formed by the adjustable capacitor in parallel (Cadj) with the parasitic input capacitance (Cp)
Therefore, we obtain:
Resulting the adjustable capacitor value:
