CW-Husky AC-coupled vs DC-coupled measurements

1

Hi, We are using CW-Husky kit for power consumption measurements. The default measurement traces are normalized to [-0.5, +0.5] on display. Does Husky provide SW configurations selecting AC-coupled or DC-coupled measurements? If not, how can we get the “raw samples” of the ADC measurements? We would like to have a direct comparison between the AC values in different traces. If the traces use different “scaling factor” in the normalization computation, then it will not give us an “apple to apple” comparison.

Thanks very much!

2

Hi,

You can get the raw ADC readings with get_last_trace(as_int=True). Traces are simply mapped from [0, ADC_MAX] to [-0.5, 0.5], so the default is consistent as well (outside of any floating point oddities).

The Husky is always AC coupled. If you’re looking for DC measurements, you’ll need to use an oscilloscope.

Alex

3

Thanks, Alex.
Is ADC_MAX the same (a constant value) for the same target board? In other words, it is a configuration parameter set in the AC measurement. All the traces use the same ADC_MAX. ADC_MAX is not the actual maximum value in the sampled data.

Thanks,
Christine

4

Yes, it’s determined by the bit depth for the ADC. It’s 4095 for the Husky (2^12-1) as it has a 12-bit ADC on it.