Hello, I am trying to interface AD5933 to a device under test in a somewhat unusual way. The device has four ports, the inputs take current and the outputs are voltages. This is still an impedance measurement, only backwards from what AD5933 expects... I first thought to convert the AD5933 output voltage to current, and then convert the device output voltage to current as AD5933 expects (Option A in the diagram below), but two conversions may not result in excellent accuracy. I am wondering, is it possible to just feed AD5933 a voltage?
From the block diagram in the datasheet, it looks like it should be possible to connect a voltage source to the RFB pin, and NOT connect anything between RFB and VIN, effectively bypassing the input current-to-voltage converter of the AD5933 (Option B in the diagram). I think the RFB voltage should be relative to whatever is at VIN, presumably using a differential amplifier or level shifter. Would this work? Is there a better way to accomplish the same goal?