Controllable DC/DC Converter

Discussion in 'The Projects Forum' started by donaldm444, Apr 9, 2013.

  1. donaldm444

    Thread Starter New Member

    Jul 16, 2010
    23
    0
    Hi,
    I'm looking for a 12 V (nominal) DC/DC converter where I can control the output voltage (by +/- 10 %) using a DC voltage control signal. I have seen numerous DC/DC converters that have a TRIM pin that allows the output voltage to be set by connecting an external resistor.

    Ideally, I would like the converter to be able to handle 3 A or more and is PCB mount. If there are any suggestions, I would greatly appreciate them.

    Thanks
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,028
    3,237
    What is the input voltage?

    Do you need ground isolation between the input and output.
     
  3. donaldm444

    Thread Starter New Member

    Jul 16, 2010
    23
    0
    The input voltage is between 8-20 V or so, ground isolation is not necessary.
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,028
    3,237
    To generate 12V output from 8-20V input and if you don't need ground isolation, you could use a buck-boost type converter (a sepic converter is one example). I don't know if such a device is available already built but if you search for "sepic converter" or "buck-boost converter) you will find information on that.

    Edit: To adjust the voltage a small amount, you can sum a DC voltage into the summing point for the error correction amplifier in the switching regulator IC.
     
    Last edited: Apr 9, 2013
    donaldm444 likes this.
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