Could you please discuss why the AD5933 has been provided with the impedance measurement method it holds. There must be some advantages refereeing to it, only that I don't really figure them out. I'm interested in finding out the theory behind it: please kindly provide titles for references (sci. articles, books, patents) comprising the method implemented in AD5933 for impedance measurement. It seems od since it works with floating test impedances, no clear chance to implement differential input and hardly imaginable with current excitation. Thank you for your best suited help! Otherwise (not that it is really a drawback) the digital part seems quite a beauty packed in a tiny (simple) package!