PWM controlled power supply

Discussion in 'The Projects Forum' started by roro36, Sep 22, 2010.

  1. roro36

    Thread Starter Member

    Sep 7, 2010
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    Basically, I am designing a switched mode power supply that is controlled via a microcontroller. Is it fine to measure the output voltage via an adc and respective voltage divider and then output a pwm to a mosfet driver to control the supply or am I missing something?
    I'll also use current control, but thats for later.
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    using a ready made chips is easier and less trouble some
     
  3. roro36

    Thread Starter Member

    Sep 7, 2010
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    0
    My project specification is to control it via a microcontroller.
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    You can do it. But keep in mind about the RAW DC that u have to use to supply primary.
    You should isolate the secondary with opto's. Resistive feed back will tend to make the secondary live in some circumstances
     
  5. tom66

    Senior Member

    May 9, 2009
    2,613
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    Your question depends on how fast the MCU and ADC is.

    If it's fast enough to react to load transients or input voltage transients, then your supply will work well.

    I think 10kHz bandwidth is probably fine. Depends on your inductor and filter cap though.

    Make the inner loop in your PWM control very fast. If you operate at 1 MIPS, then you can only get 100 instructions per cycle in.
     
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