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ADC12D1600QML-SP: Absolute Max V to RF power dBm

Part Number: ADC12D1600QML-SP
Other Parts Discussed in Thread: ADC12D1600

Is the Abs. Max RF power at Vin pins for the ADC12D1600 part found as 20*log(V*I) = 10*log(2.5*.05*1000) = 21dBm?

If not, can you please provide the appropriate equation and or RF Power max?

Thanks

  • Hi Mike

    For design calculations with respect to input signal overdrive I would recommend using the max value listed in the Operating Ratings table for Vin+, Vin- Power, "Not maintaining common mode voltage". From that table, 17.1 dBm is the maximum signal overdrive you should be targeting, especially if you can't control the percent of total operating time will be spent at that condition.

    Given the nominal full-scale input signal power of 800mVpp or approximately -0.969dBm, you have just over 18dB of headroom from the full scale signal level to the maximum allowed over-drive.

    If you need the ADC to recovery rapidly from the over-range conditions you should use the "Maintaining common mode voltage" value of 15.3 dBm for planning. This drive level is just low enough to prevent turning on the ESD protection diodes at the analog inputs and will keep the AC-coupled inputs at the proper common mode voltage.

    Best regards,

    Jim B

  • Thank you, Jim, for the quick response.

    I think I understand your answer and it is sufficient as a maximum to allow as an input and not constrain the RF design.

    However, for completeness, is my calculation correct given the Absolute Maximum Voltages listed for which damage might occur?

    Thanks again,
    Mike
  • Hi Mike
    We arrived at the RF power levels using a different methodology based on testing and simulation. It isn't possible to directly calculate the powers based on the Min/Max voltage levels listed.
    Best regards,
    Jim B
  • Understood.

    Thank you.

    Any way to determine if it will survive at those power levels, when turned off?  do the ESD Diodes protect even if not biased?

    Thanks

    Mike