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ADS1198: P2P with ADS1298?

Part Number: ADS1198
Other Parts Discussed in Thread: ADS1298

Our customer plans to open a new product of ECG monitoring, which needs an 8-channel low-power ECG scheme. We plan to use ads1298 to design and be compatible with ads1198 at the same time. Will ads1198 and ads1298 be P2P compatible and whether the external circuit design is the same?

  • Hello if anyone give me a answer?

  • Hi,

     Sorry for the delay.

     It depends on to what perspective you want to say they are compatible.

     Do you have/use ADS1198 and ADS1298 evaluation board/kit(EVM)? 

     I may say, ADS1198 is less compatible with ADS1298 if compare ADS1298 with ADS129(4,6).

    Don't know if you care about the respiration function as ADS119x family doesn't have respiration functions/pins; if don't care about the Respiration functions/pins, the external circuit design could be similar; however, please refer to the layout guideline and suggestion in both data sheet and EVM user guide(https://www.ti.com/lit/ug/sbau171d/sbau171d.pdf?ts=1653425259296&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FADS1198)

    ADS119x family and ADS129x family have different ADC - 16 bit ADC vs 24 bit ADC;  and support different data rate ranges -

    And, there are at least the following timing constraints if people use DOUT pins - 

    it may require some firmware code change; however, I suggest rework several PCBAs with ADS1198 and ADS1298 and do some tests to compare and evaluate the results and performances.

    Thanks

  • Our customers have not purchased EVM board yet. At present, we need to select the scheme first and then purchase the corresponding EVM board for testing.

    Our customers still have the following questions. Can you give us a simple answer?

    1、 Is there a reference conditioning circuit from 12 lead ECG electrode to ads1198 differential input?

    2、 If software pacing detection mode is selected, is there a corresponding reference circuit? Compared with hardware and software pacing detection methods, which one has higher power consumption? Which internal resources consume more?

    3、 What are the implementation methods of electrode falling off detection? Whether reference circuit is provided.

    4、 The customer needs to eliminate the common mode noise of differential input signal caused by human body or environmental noise. Is there a corresponding guidance document.

    5、 Do external hardware circuits (such as anti aliasing circuits) need to be adjusted under different sampling frequencies? How to adjust the optimal?

    6、 Where can I download the AFE reference circuit and PCB of 12 lead ECG acquisition scheme?

  • Quoted and embedded comments  below -

    1、 Is there a reference conditioning circuit from 12 lead ECG electrode to ads1198 differential input?

    Comments: generic reference circuit can be found in ADS1198 EVM and User guide - www.ti.com/.../sbau171d.pdf

    2、 If software pacing detection mode is selected, is there a corresponding reference circuit? Compared with hardware and software pacing detection methods, which one has higher power consumption? Which internal resources consume more?

    Comments: For software pacing detection, people can refer this for reference - https://www.ti.com/tool/TIPD197#design-products

    and Page 93 to 96 in ADS1298 datasheet.

    Regarding to power consumption comparison, there is no definite answer as there are many designs trade-off depending on the products needs/spec. E.g. sensitivity, specificity, monitoring/sensing/triggering frequency, whether the customer's ucontroller/processor already has a sufficient differential ADC, crystal oscillator and various factors, etc. People may implement both during prototype stage and collect data/study/compare/evaluate. 

    3、 What are the implementation methods of electrode falling off detection? Whether reference circuit is provided.

    Comments:ADS1198 EVM and User guide shows brief demo for the lead/electrode Off features. In addition, people can take a look of the following -

    https://www.ti.com/lit/an/sbaa196a/sbaa196a.pdf?ts=1653491405588&ref_url=https%253A%252F%252Fwww.google.com%252F

    https://training.ti.com/electrocardiogram-ecg-lead-detection-wearable-devices

    4、 The customer needs to eliminate the common mode noise of differential input signal caused by human body or environmental noise. Is there a corresponding guidance document.

    Comments: People can refer to /cfs-file/__key/communityserver-discussions-components-files/73/Improving-Common_2D00_Mode-Rejection-Using-the-Right_2D00_Leg-Driver-Amplifier.pdf

    and search for right leg drive or circuit online.

    5、 Do external hardware circuits (such as anti aliasing circuits) need to be adjusted under different sampling frequencies? How to adjust the optimal?

    Comments: Possible and it may depend on designers/engineers and products designs, environments, electrodes, cabling, patients skin etc to adjust, collect data, study, analyze, tune before making final decisions.

    6、 Where can I download the AFE reference circuit and PCB of 12 lead ECG acquisition scheme?

    Comments: TI doesn't provide raw/source designs files, please refer to EVM's user guide.

    I am closing this ticket for house cleaning as the questions & discussions already moved to different topics.

    Please feel free to open another ticket.

    Thanks