How to feedback the class D?

Discussion in 'The Projects Forum' started by catherine, May 15, 2007.

  1. catherine

    Thread Starter New Member

    May 15, 2007
    3
    0
    For a Class D PWM audio amplifier (differential stage and power stage), what is the easiest feedback scheme?

    Since the output of the power stage is a modulated pulse waveform, where should I feed this into?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
  3. catherine

    Thread Starter New Member

    May 15, 2007
    3
    0
    you are so kind! thanks a lot!
     
  4. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
  5. catherine

    Thread Starter New Member

    May 15, 2007
    3
    0
    I have paste the main architecture in attach file, please help me!
     
  6. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    It almost appears as though the first stage is set up as a Delta-sigma converter.

    The design looks like it is a mix of PWM and Delta-sigma.

    hgmjr
     
  7. Distort10n

    Active Member

    Dec 25, 2006
    429
    1
    Well, for first and last questions:

    1) Yes, you can but if you neglected to use Rf then you would have unity gain.

    4) I think filterless Class D amps ultilize the speaker inductance to help filter rather than using external bulk caps.
     
  8. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Greetings catherine,

    I fixed the link in my earlier reply. The article has some pretty interesting information in it.

    hgmjr
     
  9. DrNick

    Active Member

    Dec 13, 2006
    110
    2
    look up cherry-hoopers, they may help with your feedback loop from your Full bridge
     
Loading...