Hi everybody,

I'm evaluating the AD7745 and since it gives me wrong values I am going to calibrate it. Unfortunately I did not understand the procedure. Datasheet says I can connect a "zero-scale capacitance", but what does it mean? I tried with a short but it saturates, what is a zero-scale capacitance?

The second method is to "calculate and write the offset calibration register value", yes but with which value? What I have to calculate?

Thank you for your help.

Sangi

Hi

can you please let me know the range of the capacitance you are trying to measure?

also how do you know the values are not correct, say if you connect a 4 pF capacitance what is the CDC reading it as?

thanks