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.

LMK1D1208: Maximum Input Power for Sinewave Signal on LMK1D120X

Part Number: LMK1D1208

Tool/software:

Hello,

I am currently working with the LMK1D120X evaluation board and using a single-ended (SE) sinewave as the input signal.

The datasheet specifies input voltage levels for square-wave signals (0.4 V to 3.465 V), but I would like to confirm:

  • What is the maximum allowable input power for a sinewave signal?

  • Are there additional considerations for AC-coupled vs. DC-coupled inputs?

I want to ensure I stay within safe operating limits while optimizing signal integrity.

Thank you for your support!
Best regards,

Carlos Couso

  • Hi Carlos,

    I can understand your concern.

    There is no specified input power for the LMK1D120XEVM. That being said, the specification for single-ended input swing can be used to derive a max input power. Calculating the RMS voltage of the peak signal (a 3.465Vpp square wave) as 2.45Vrms, the equivalent power in dBm is ~20.7dBm - which should be regarded as your maximum input power for any sinusoids or square waves being input.

    The additional considerations for AC vs. DC coupled inputs are encapsulated in section 9.4.2 of the datasheet. Main thing of note is that if you are driving single-ended, the inverting input must be held at the midpoint of the input swing.

    Thanks,

    Michael