• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 526 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

Selecting an interface for the ADS6445

Karen
Intellectual 940 points
Other Parts Discussed in Thread: ADS6445, THS4508, THS4509, THS4511, THS4513

I have to design an analog interface to the ADS6445 (quad, 14-bit, 125MSPS ADC).  Below are the requirements that I have to meet: 

1.       DC coupled

2.       Single supply

3.       Bandwidth = 0Hz to 250MHz ideally but at least 0Hz to150 MHz.

4.       Vocm = 1.5 V

 Could you suggest a part suitable for this application?

 

  • 0
    TI__Intellectual 940 points

    The best devices for this application would be the fully differential family of THS4508/9/11/13.

    They are all based on THS4509 core with tweaks to suit different applications.

     

    They will all be good ADC drivers for a DC-coupled amp/ADC interface. For the optimal dynamic range and distortion it would best if you can power the chips with a {-1V,+4V} power supply. This will put the natural output common-mode of the amp near the input common-mode of the ADC. This will be especially important for a high-bandwidth application like this were the amp is going to challenged to meet the distortion performance of the ADC at the higher signal frequencies.

     

    The THS4508 and THS4509 have minimum stable gains of +6dB. However if you need unity gain then you would use the THS4511 or THS4513.

     

    Aside from gain, the driver for the device selection will be how you will provide the signal to the amplifier. If the input is AC-coupled, then the THS4509/13 would be best. If the signal source will be DC-coupled to the amp, then it might be best to consider the THS4508/11. I hope this helps.