Why in 4 wires example, Auxiliary channel and Temperature channels need calibration?
I presume you mean the ImpedanceMeasurement_4WireBioIsolated example? This example is a little different from a typical impedance measurement. Rather than go into the details here, I will point you to our applications note, AN-1302, for a detailed explanation.
In this example, the ADuCM350 performs a current measurement using the internal TIA and a voltage measurement using an external instrumentation amplifier. The Aux Channel calibration is required as one of the aux channels is used for the voltage measurement. For the current measurement, we only needed to do the first 2 steps of the TIA channel calibration routine. The Temp Sensor calibration routine actually does this, so rather than write a new routine, we reused the temp sensor one!
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