ADS1299: How to Measure Impedance of Active Electrodes

Part Number: ADS1299

I am experimenting with TI ADS1299 evaluation kit for EEG acquisition. I see the that ADS1299 has provisions for measuring electrode impedance with the skin to validate the measurement. The electrodes I shall be using are active dry electrodes which have inherent unity gain amplifier. I understand that methods used with 1299, like injecting small currents, are suitable only for passive electrode without electronics and connected directly to ADS1299.  Can You recommend a method / application suitable for measuring electrode to skin impedance with active electrodes which have electronic buffers  inside.

1 Reply

  • Hello Shai,

    Thank you for your post!

    Unfortunately, we do not have a recommended solution to offer when there are additional active components in the electrode signal path. Are you sure that you need the active electrodes with the ADS1299? The dynamic range offered in the ADS1299 should be more than enough for most biopotential applications.

    Best Regards,

    Ryan Andrews

    Precision ΔΣ ADCs