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LM97937: DC level on ADC output

Part Number: LM97937

Hi team,

My customer wants to understand the how much is the max DC level LM97937 could make on ADC output, both in burst-mode and SNR-Boost mode.

Could you kindly help?

Thanks!

  • Hey Luke,

    Are you asking for the max DC offset tolerable at the ADC output? If so, are you using the device with DC offset correction enabled?
  • Hi Yusuf,
    I mean the max ADC output's DC level.
    If DC offset correction is disabled or enabled, how much will be the ADC output DC level?
  • Hey Luke, 

    To find the max DC offset i used the absolute maximum ratings in the datasheet. 

    Given that Vcm is a recommended 1.6V and full scale range is a differential 1.7Vpp, you can derive the maximum offset by using the highlighted absolute maximum voltage for the input signals A & B. 

    Absolute minimum input pin voltage is Vcm -1V = 0.6V 

    Absolute max input pin voltage is  Vcm + 0.75V = 2.35V

    At full scale range of 1.7Vpp differential, the maximum DC offset is at least  2*( 2.35 - (1/4FSR+1.6V)) = 0.65V. Now convert to dBFs. 20log(.65/1.7) = -8.35dBFs for max DC at output with a common mode voltage of 1.6V