Part Number: ADS1298R
HI TI Exports,
I am designing an ECG front end using the ADS1298R and would like to confirm the correct usage of the respiration impedance feature from a hardware perspective.
In our design, the ECG electrodes are connected through a symmetric, high-impedance analog front end (DC blocking, RF filtering, and unity-gain buffering) before the ADS1298R inputs. No aggressive analog low-pass filtering is applied prior to the ADC, and the RLD loop is implemented per TI recommendations.
Our question is regarding simultaneous ECG and respiration acquisition from the same electrode:
• Can the ADS1298R acquire normal ECG data from a channel while simultaneously using that same V6 electrode as part of the respiration impedance measurement (e.g., RA–LA or RA–LL excitation)?
• Is the respiration demodulation path fully independent of the ECG signal path inside the ADS1298R, such that ECG voltage (low-frequency biopotential) and respiration impedance modulation (32/64 kHz carrier) can coexist on the same input without external signal separation?
• From a hardware standpoint, are there any restrictions on external input filtering, buffering, or electrode routing that would prevent reliable respiration tracking when ECG is measured from the same lead?
The goal is to confirm that no additional external switching or dedicated respiration electrodes are required, and that both ECG and respiration data can be obtained concurrently from the same electrode set.
Thank you for your guidance.
Best regards,
Jay R Chotaliya
