This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Part Number: ADS1298
We are using the ADS1298 with 8 differential inputs, the primary use is for EEG measurements. However, one of the requirements is that our design shall be configurable to measure the standard ECG signals as well, i.e. Lead I, II and III and the Wilson connection. This requires the MUX of the device to be able to internally route the inputs from one channel to the INA of another channel. Specifically, the RA signal should be available on the negative input of two INAs to be able to generate LA - RA and LL - RA directly. An example of this is presented in the following training video;
"How to measure ECG - ADS129x product familyhttps://training.ti.com/how-measure-ecg-ads129x-product-family?cu=1128637
In this video (about 1.04 into the video) there is a figure showing 12-lead ECG with ADS1298. It shows that the RA electrode is internally configured to be routed to INA's of two different channels, to generate Lead I and Lead II (LA - RA and LL - RA, respectively).
However, I am not able to find out from the ADS1298 data sheet how to configure this routing internally. In section 188.8.131.52 Input Multiplexer (p. 27) or 184.108.40.206 CHnSET: Individual Channel Settings (p. 71) there seems to be no sign of this functionality.
So my question is whether it is actually possible to internally configure inputs from one channel to be connected to the INA of another, and if so, how is it done?
Interestingly, I see in the data sheet for another device in this family, the ADS1293, that it is described how to easily do this (p. 63-64).
Thanks for your help!
Thank you for your post and welcome to our forum!
The ADS1298 actually does not allow you to reroute input signals to different channels as suggested by the figure in the presentation. Initially, the block diagram was used to illustrate the signal chain for 12-lead ECG applications. The dotted line suggests how much of the signal chain is integrated in our device. In practice, RA must be externally shared amongst multiple channels to derive Lead I and Lead II. An example of this is shown in our ADS1298ECGFE-PDK User Guide:
On the other hand, the ADS1293 does allow you to route any input signal to any channel. This is the benefit of the Flexible Channel Routing registers (01h to 03h).
Thank you for pointing this out!
Applications Engineer | Precision ADCs
Are you working on a bio-potential application? Check out these helpful resources: ADS129x BIOFAQ | ECG Online Training
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.