FRA variable output amplitude over frequency ranges

Hi, I recently got a Moku:Go and I love it so far. My use case is mainly to measure loop gain response of dc-dc converters. One missing feature is the ability to manually adjustable output sweep signal amplitude over the measurement frequency range.

At low frequencies the gain of the converter control loop is huge, and requires a large injection voltage to get measurable response at the noisy switch mode regulator output. At higher frequencies, a high amplitude injection signal can cause non-linearities and corrupt the measurements, or even drive the power converter into a different control scheme.

Although there is an automatic dynamic amplitude feature in the moku FRA tool, it only adjusts the output amplitude to prevent saturation of the input channel. It does not allow for user-defined adjustment of the output amplitude over frequency to maximise signal to noise ratio, or minimise distortion of the device under test.

What would be nice is to have an editor for users to set the signal generator output amplitude at various frequency points. This feature is common in other FRA tools on the market, for example the Omicron Bode 100 or even the built-in FRA tool on my Siglent oscilloscope.

Hi @topQuark12 Alex,

I will make a feature request this for functionality. As for now, the workaround is using the Moku API to define the amplitudes of the drive signals section by section. Then, stitch the sections together to make a complete frequency response plot.

Please let us know if you have any questions, we will be more than happy to help!

Best regards,