Wavegen and Scope values do not match.

[MarcusD]

Hello.

I am using the Analog Discovery 2 (Scope: 2 x 8k, Wavegen: 2 x 4k) to create a 13.5 MHz sinus signal (2 Vpeak-peak).

However, my measured signal has a much lower amplitude (slightly less then 80mV) and I am wondering what's going wrong. 

(reducing the frequency to 1 MHz leads to 1.6Vpp) 

 

Edited March 15, 2022 by MarcusD
Additional information

[attila]

Hi @MarcusD

High frequency signals get attenuated due to bandwidth limitations, more on Wavegen output than on the Scope input for AD2, see:
https://digilent.com/reference/test-and-measurement/analog-discovery-2/hardware-design-guide#awg_spectral_characteristics
https://digilent.com/reference/test-and-measurement/analog-discovery-2/hardware-design-guide#scope_spectral_characteristics

[MarcusD]

@attila Thanks for your quick response.

So I can trust the Scope on the measurement and adjust the amplitude until it reaches the desired Vpp?

[attila]

Hi @MarcusD

Not entirely since the scope input also has bandwidth limitation, it also depends on the tested circuit, the load/wire characteristics...