AFE current shunt burden voltage compensation

[prasimix]

Low-side current measurement will be used when measuring power and efficiency using MIO+AFE. In this case the voltage and current AIN- should be at a common potential. Here we have a problem of accuracy of voltage measurement on DUT because the measured value will include current shunt burden voltage U(AI3) (i.e. voltage drop on current shunt).

Therefore, two things need to be done:

• [ ] Add a burden voltage compensation option on voltage channels (question is how to name this button) when the burden voltage will be subtracted from the measured voltage value.
• [ ] Add burden voltage calibration for current inputs (i.e. AIN2, AIN4 for AFE1, AFE2 or only AIN4 for AFE3). Calibration is likely to require measurement at only one point for a current that is half the scale of the current range being calibrated).

[prasimix]

Another possibility comes to mind: using another voltage input (i.e. AI1) to measure the actual burden voltage to be used for compensation:

Burden voltage compensation should offer selection of current input used for power or efficiency measurement, or voltage input for above mentioned 3-channel method.