ADS1299: ADS1299 reference circuit Bias_SHD and Bias_DRV connection question

Hi

May I ask do you have/use a ADS1299 evaluation board/kit/EVM?

I suggest try and do the experiment and tests with a EVM and a ECG simulator first to get more understanding and familiar with system behavior.

By setting 0xff to BIAS_SENSP and BIAS_SENSN registers, it means you close all the BIASnP and BIASnN mux/switches in Page 33 Figure 38 in data sheet.

Doing this doesn't always guarantee to significantly improve the noises. Usually designers/engineers need to test these register configurations through a series experiments, trials and analysis with ECG simulator first to figure out the proper combination/configurations depending on cases by cases that are up to designers/engineers electrodes, environmental noises, cables, skin conditions, boards designs, etc.

Designers/Engineers usually need to do extensive experiments and study to compare different register configurations.

Using RLD or not heavily depends on the applications and environments and setups, it's not easy and too early to say RLD will definitely significantly improve the noises or not; experiments and analysis are required before making decisions.

I suggest start 1 pair of electrodes only, i.e. one lead (e.g. RA->LL), and do experiment/tests/analysis to compare between toggling the BIASnP and BIASnN mux/switches only for that channel to study and understand before turning on/moving on to use RLD.

Because how much RLD can really help to improve noise is firstly depending on your raw signal integrity, and depends on the electrodes, environmental noises, cables, skin conditions, boards designs, setup, etc; which may affect how you want to configure the gains, muxes/switches and the integrator circuit shown in the schematics.

Thanks.