Differential Input Configurations For AD9650

Dear Sir or Madam

As I found in the datasheet page31 of AD9650 , it mentioned "For baseband applications, AD8138, ADA4937-2, and ADA4938-2 differential drivers provide excellent performance and a flexible interface to the ADC."

Does it mean that only these three drivers can perform excellent for AD9650  with Figure 79 connection ? 

Example, can't  LTC6417 perform better or equal than those three (AD8138, ADA4937-2, and ADA4938-2 )  in unity gain ?

Are there some points I should  take carefully on choosing a  ADC driver?

Thank you 

sincerely

Anglic

  • 0
    •  Analog Employees 
    on Dec 4, 2019 2:27 PM

    Hello,

    The amplifiers mentioned in datasheet were ADI amplifiers available at the time of release of the AD9650 when LTC was a separate company before joining ADI a few years ago.  Based on the datasheet of the LTC6417 and results they show  on 1st page with LTC2209, it would appear to be a better choice especially when digitizing high IF input signals.   Ideally one choses the amplifier such that it meets your overall system requirements (measured by ADC's performance in terms of SFDR, SNR, noise floor, IMD, ext).   A quick look at the LTC2209 datasheet suggests that it would not limit the ADC's performance (esp when a band limiting filter is used between devices to filter out of band noise from aliasing back).