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.

ADS4149: Schematic Review

Part Number: ADS4149
Other Parts Discussed in Thread: OPA857, THS4541

Hi,

PFA the schematic for ADS4149.

Kindly review the schematic.

Regards,

Jainendra 

OTR_SCMPDF_ADS4149.pdf

  • Hi Jainendra,

    This schematic looks fine to me. I don't see any issues.

    Regards,

    Rob

  • Hi Rob,

    Thanks for your feedback.

    We have used ADS4149 interfacing with the device part#THS4541RGT. Is it ok?

    One more part #OPA857 has been used with the part#THS4541RGT.  Is it ok?

    Kindly review the schematic.

    Regards,

    Jainendra  

    OTR_SCMPDF-ADC4149_12.pdf

  • Hi Jainendra,

    Not sure the common mode voltage will work between the THS amplifier and ADC. I am forwarding this onto the amplifier team to review.

    Regards,

    Rob

  • Hello Jainendra,

       ADS4149 requires a pretty low input common-mode voltage of 0.95V. The schematic you shared shows that you are setting the VCM of the THS4541 to 0.95ishV via voltage divider which is correct. However, do take note of decrease in distortion performance and lower I/O headroom due to the deviation from common mode of VS+/2. Please read Section 8.3 in the THS4541 datasheet for more details. 

      Otherwise, your schematic looks good. At the output of the amplifier, it looks like you are AC coupling, so depending on your input signal, you may instead set VCM to VS+/2 for better performance, and then set output stage post DC-blocking caps to 0.95V (ADC VCM).

    Thank you,
    Sima