EVAL-AD7982-PMDZ, High THD-3 level.

I 'm testing Eval-ad7982-pmdz and comparing THD results with Eval-7984-pmdz. 

In contrast to charts provided in datasheets, adc7982 shows worse  results in exactly the same test conditions.

Difference is more than 10 dBc  with 2 kHz sine signal. 

AD7984 = -115 dBc

AD7982 = - 105/ 108

What I discovered, logo printed on IC is different. Since EVAL-ad7984 I bought 2 years ago, my question is:

-Does AD change logo in the last 2 years?

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  • 0
    •  Analog Employees 
    on Apr 28, 2021 10:59 AM

    Hi, 

    Can you share more about your setup/ test conditions, equipment used, etc.? 

    Apologies. We do not provide information regarding part markings on EngineerZone. We suggest going back to your point of purchase to get this information. Note that ADI only provides warranty coverage or any quality, reliability, failure analysis, applications, or other support on products purchased through ADI authorized distributors and sales offices. To ensure you are receiving unused, legitimate ADI product, please ensure all purchases are made through the ADI authorized distributors and sales offices listed on our website at: Sales and Distribution | Analog Devices 

    Thanks for understanding.

    Jellenie

  • Hi,

    ADC board was interfaced to Nucleo-stm32H743zi2 , FFT size 32k. Test setup is irrelevant, since both ADC evaluation boards were tested in exactly the same conditions. Simply, replacing one unit for another w/o changing any single wire connection. Actually, I used 3-rd module Eval-AD7693-pmdz (with correct markings) for verification small nuances.

    Eval-AD7982-pmdz I have issue with , was bought over AD official distributor, listed on a web page you provided:

Reply
  • Hi,

    ADC board was interfaced to Nucleo-stm32H743zi2 , FFT size 32k. Test setup is irrelevant, since both ADC evaluation boards were tested in exactly the same conditions. Simply, replacing one unit for another w/o changing any single wire connection. Actually, I used 3-rd module Eval-AD7693-pmdz (with correct markings) for verification small nuances.

    Eval-AD7982-pmdz I have issue with , was bought over AD official distributor, listed on a web page you provided:

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