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AD633 analog multiplier IC and AM generation.

  1. Dec 16, 2012 #1
    Hi PF,
    I used the circuit shown in datasheet of AD633 to generate AM waves. But the output I got was not correct. I want to why this error comes and explanations will be helpful. I will have to go for BF194 designs else. Here in our labs transistor circuits seldom works. Why I don't know? Please help. I am attaching the circuit and o/p waves.

    TIA

    -Devanand T
     

    Attached Files:

  2. jcsd
  3. Dec 16, 2012 #2
    This looks like a problem in whatever you're using to simulate a scope.. signals don't just 'end' like that, jump to the side, resume, end again, and jump back. Defective scope software does though.
     
  4. Dec 16, 2012 #3
    Looks like your "Y" input is not making it into the AD633. Check connections to pins 3 and 4.
     
  5. Dec 17, 2012 #4
    I am not using any simulation s/w, this is the cro o/p I reproduced by drawing...
     
  6. Dec 17, 2012 #5
    The waveform looks like modulation is superimposed (added to) carrier instead of modulating the carrier. This will happen if the carrier is making it into Z but not into Y1. Check your Y1,Y2 connection.

    What frequency are you at?
     
  7. Dec 17, 2012 #6

    jim hardy

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    The picture that appears on my screen shows bottom half of measured output wave shifted right by about seven carrier cycles.
    If i shift it left to where it aligns, i see a wave that looks just like "expected".

    I would diagnose that as a computer software malfunction or misadjustment.

    What kind of device are you using to capture that wave?

    I dislike computerized oscilloscopes for basic work.
     
  8. Dec 17, 2012 #7
    I cut copy shifted the image of wave to resemble the wave I got in real CRO...It is not a software generated output.
     
  9. Dec 17, 2012 #8

    jim hardy

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    What emi guy said...


    well, get it working one piece at a time.

    Set Em to zero and see if carrier Ec is making it through...

    then try very small increments of Em,

    is what i'd do.
     
  10. Dec 17, 2012 #9
    will try....
     
  11. Jul 1, 2013 #10
    the circuit diagram has no error.
     
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