• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 343 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

ADS 1298 Demonstration Kit usability for EEG?

Howard Letovsky
Prodigy 10 points
Other Parts Discussed in Thread: ADS1298, ADS1299

I am considering testing the ADS1298 chipset for EEG use. However, the demonstration kit specification suggests that it is designed for ECG use and there is only a max gain of 12. This would be useless for EEG.

I also was interested in pulling a simultaneous analog output from the input amps - either combined from all input channels , or individual channel selectable. It appears that there is a dual PACE output - but again, the data sheets are very unclear as to the functionality of the chipset and demonstration board for EEG.

Please contact me directly at mail@howardletovsky.com, or by phone at 707-481-5252.

I am currently using a stack of Grass EEG amplifiers, a wideband mixer, and an AD Instruments ADC system to do what I want. It works phenomenally well, but I wanted to see if it is possible to scale the electronics down to a more portable size.

  • 0
    TI__Guru 66166 points

    Hi Howard,

    The ADS1298 would only be a viable solution for EEG if you precede it with a low-noise gain stage. As you noticed, the largest gain is only PGA = 12. At 250SPS, the input-referred noise level is quite low (~2.4 uVpp) so this could work for EEG.

    The PACEOUT pins provide a way to route the PGA outputs to external circuitry directly. Each PACEOUT pin can output one positive or negative channel input, buffered by an internal amplifier with a gain equal to 0.4. These outputs were originally intended to connect to an external slope detection circuit for pacemaker detection. What was your intention for using these pins?

    Lastly, have you considered the ADS1299? The input-referred noise is as low as 1uVpp and offers a gain up to PGA = 24 (external gain may still be needed). The features are similar to the ADS1298, but AC performance is generally better.

    Regards,