FFT in LTSpice

Discussion in 'General Electronics Chat' started by atferrari, Jun 4, 2011.

  1. atferrari

    atferrari Thread Starter AAC Fanatic!

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    LTSpice

    I am confused about this: what it is the actual reference (0 dB) as shown in the graphic of a FFT from a certain signal?

    In other words, the level of the harmonic content, is it compared to what?
  2. debjit625

    debjit625 Active Member

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    Normally the FFT shows the result in decibel but you can change the unit to Volts or Amp,use "linear" option to repersent the magnitude.To, get the option window in LTSpice click on the decibel units on FFT window.

    Good Luck
  3. Ron H

    Ron H E-book Developer

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    I ran a little experiment on a 1kHz sine wave. 1V RMS = 0 dB.
  4. atferrari

    atferrari Thread Starter AAC Fanatic!

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    Yes Ron, I was suggested to do a FFT exactly on that. It is clear for me now.

    Good Luck, thanks for your reply as well! :D Have to experiment with all that.
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