Good morning, I have a question. We are interested in buying the AFE4300 chip for bioimpedance measurement. I wish to know what is the range of impedance measurements (minimum and maximum Resistance that can be measured) without using an external front-end and at what frequencies.
In our application we have to measure resistance of around 30 ohms with an error of less than 1 ohm
Giuseppe,
You can change the values of the resistors to calibrate the AFE4300EVM for less than 100 ohms. There is an app note in our product folder online that will help, http://www.ti.com/litv/pdf/sbaa202. You should keep in mind the location of each resistor since some are parallel to eachother. I have attached a picture of the circuit so you will know how it looks and so that the resistor math can be done accordingly.
The software will calibrate it correctly because the values of hte resistors are not hardcoded in our GUI. They are available to change by the user. This is show on page 8 of the app note I liked you to in the earlier post. I have also included a screen shot of the BCM Measuremet tab and you will see in the bottom left side there is a spot to change these resistor values.
Unfortunately we do not release our Labview source code, however if you wer eworried about not being able to calibrate correctly you shouldn't need it.
