• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 47 subscribers
  • Views 147 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.

THS4551: Design Inquiry

Abhishek Manoj
Intellectual 465 points
Part Number: THS4551
Other Parts Discussed in Thread: THS4552, ADS127L18, ADS127L14, THS2630

Hi Team, 

I was planning to use the amplifier THS4551IRGTR for the input of my ADC IC AD7768.

My required input range is +/-4V for the ADC signals.

The input of the amplifier will be single ended signal coming from the mixer IC AD630ARZ.

Can i use this amplifier to convert my single ended output to +/-4V input range of my ADC.

The below mentioned is the block diagram of my requirement.

image.png

Regards,

Abhishek

  • 0
    TI__Mastermind 24079 points

    Hello Abhishek,

    Yes,  the THS4551 can be used for single-to-differential conversion and drive the appropriate differential input range & the ADC common-mode.

    Can you clarify from your block diagram if the mixer output is being driven by a single FDA into both the 8-channel ADC and 4-channel ADC?  A better architecture here would be do use two FDAs, which can be two single ICs or a dual-FDA such as THS4552.

    Are the two 24-bit converters differential inputs?  What sampling rate/speed would you be using on these converters?  Do you have a target effective number of bits (ENOB)?

    Is there also a total harmonic distortion (THD) or signal-to-noise ratio (SNR) for this piece of the signal chain?

    The AD6678 ADC type is delta-sigma with fully-differential inputs.  I would recommend that while you consider THS4551 and THS4552 as your first FDA options from my team, I also hope you consider the TI ADS127L14 and ADS127L18 delta-sigma converters from TI to potentially replace the existing ADCs, as they are competive in this application.

    Please let me know any additional questions or share updated details as you are able to do so.

    Thank you Abhishek.

    Best,

    Alec

  • 0 in reply to Alec Saebeler
    Intellectual 465 points

    Hi Alec,

    There is a total of 12 mixers, I'm planning to use 12 input amplifier for each mixer output.

    The sampling speed required is 256KSPS per channels of ADC and the ADC needed is 24-bit.

    I want the amplifier each of the 12 THS4551 should take single ended output from the 12 mixer AD630ARZ. The output of the amplifier THS4551 need to be differential signals, so that i can directly connect the differential signals to AIN+ and AIN- pins of the ADC IC.

    Please confirm whether i can use THS4551 for the above requirement.

    The board should emit less noise and EMI/EMC compliant as it is used as a precision medical equipment.

    Regards,
    Abhishek

  • 0 in reply to Abhishek Manoj
    TI__Mastermind 24079 points

    Hello Abhishek,

    The THS4551 and dual-FDA THS4552 would be options for this design.  I do want to highlight and recommend our higher voltage THS2630, which is lower noise and may offer benefits for the medical equipment use-case of the design.

    These two fully-differential amplifiers (THS4551/2 and THS2630) are both capable of providing the system-level performance you require at 256KSPS.

    Please let me know your additional questions or concerns.

    Best,

    Alec