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ADS1147: Crosstalk between adjacent channels

Part Number: ADS1147
Other Parts Discussed in Thread: ADS1247

Dear Specialists,

My customer is considering ADS1147 and has a question about input channel crosstalk.

I would be grateful if you could advise.

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I have a question about the internal multiplexer of the ADS1247.

What is the crosstalk characteristic of adjacent channels in dB?


For example, when the maximum voltage is input to AINP1-AINN1 and the minimum voltage is input to AINP2-AINN2 and A/D conversion is performed, what is the effect of crosstalk?

A typical multiplexer has about 90dB of crosstalk between adjacent channels, but I think this is insufficient.

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I appreciate your great help in advance.

Best regards,

Shinichi

  • Hi Shinichi Inoue,

    I don't have any data to share with respect to crosstalk on the ADS1147 (or ADS1247?)

    However, the customer can perform this test if they want to characterize their own system. They can apply 0V to CH1 and 0V to CH2, then apply 0V to CH1 and 5V to CH2, and compare the results.

    The challenge with this approach is that they also need to consider the ADC noise and offset error in their measurements. Since the noise depends on the ADC data, they will also need to consider the ADC data rate too. So it is not as straightforward as calculating the crosstalk for a discrete mux, since the ADC mux does not have accessible output pins.

    I unfortunately cannot perform these tests on my own EVM as I am waiting for a new one to arrive.

    Let me know if your customer has any questions about how to perform the crosstalk test.

    -Bryan

  • Hi Bryan,

    Thank you for your reply.

    I understand there is no data for crosstalk.

    I'll share this information with the customer.

    If they have an additional question, I consult you another thread.

    I appreciate your great help and cooperation.

    Best regards,

    Shinichi 

  • Hi Shinichi Inoue,

    Yes, please let us know if anything else is needed

    -Bryan