Best ADC for High voltage inputs?

I’m trying to decide which ADC to use for a high voltage front end.  Here are the requirements for the ADC:

Fixed input range +/- 50V

16 bit resolution

10 Meg input impedance

1 MHz Bandwidth

2 or 3 MSPS or greater

Serial or SPI output

I’ve been looking at the following ADCs:

AD7985

AD7961

AD7626

AD7625

AD7622

Any suggestions?

  • 0
    •  Analog Employees 
    on Nov 17, 2014 9:56 PM

    Hi,

    I'm not aware of any ADCs that can directly support what you have described, especially the input range.  So I would suggest exploring some ADCs which support the requirements of your application (for example the signal to noise ratio, SPI outputs), and then explore what analog signal conditioning would be required to interface to the ADC you choose. 

    Also, the high speed ADC community is likely not the best starting point for <10Msps, so I moved this post to the precision ADC community.  Hopefully someone here can help. 

    Regards,

    David

  • 0
    •  Analog Employees 
    on Nov 20, 2014 1:26 AM

    Hello Paul,

    The AD7625 or AD7626 would be a good fit for you application if you can deal with an LVDS interface, which allows you to use higher input frequencies (e.g. 1MHz). I presume that you would use some kind of signal conditioning to level shift the high voltage +/-50V input range to fit within ADC input FS range.

    Regards,

    Maithil

  • 0
    •  Analog Employees 
    on Nov 20, 2014 2:47 PM

    Regards,

    ClaireL

  • Maithil,

    Thanks for the suggestions.  I'm leaning toward the AD7626.  Yes, I will be adding some type of level conditioning before the ADC (maybe a simple voltage divider).  I am considering purchasing the evaluation board EVAL-AD7626FMCZ.

    Does anyone know where I can find the schematics for it?

    Thanks,

    Paul

  • 0
    •  Analog Employees 
    on Aug 2, 2018 2:49 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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    EZ Admin