Analog Discovery 2 - frequency sweep resolution question

[longboard]

Hello,

I am using the AD2 for generating a 80-60kHz sinusoidal linear sweep over a 40mS span. I am trying to understand how to determine the frequency resolution during the sweep. I have read the post below. I understand that the DAC output rate is 100MHz. But I am struggling to understand the carrier buffer index increment amount and how to calculate the number of frequency steps in my sweep. I appreciate any help possible.

Thank you

Sean

 

[attila]

Hi @longboard

The maximum number of AM and FM steps is given by the AM/FM buffer size.
For AD2 with the default configuration is 2k.

[longboard]

Hi Attila,

Thank you for that information. I found the control for the buffer size under 'Settings' > 'Device Manager'. From there I can see the 8 different options to select from. It appears as though the max for the 2 waveform channels is 16K. So for my sweep of 20kHz does this mean that there is a 20,000/16,000 or 1.25 Hz resolution?

Thank you

Sean

[attila]

Hi @longboard

For AD2 in the 3rd configuration the Wavegen carrier buffer is 16k (16384) but the AM/FM buffers remain 2k (2048).

[longboard]

Hi Attila,

Thank you for clarifying. So for my sweep the device should then have 20,000 / 2048 = 9.765 Hz.

Sean