DC/DC Converter Common Pin

Discussion in 'The Projects Forum' started by Alex009, Aug 11, 2014.

  1. Alex009

    Thread Starter Member

    Jul 2, 2014
    Hey guys,

    I'm using the DC/DC-Converter TMR1-2422 from Traco Power (Dataseheet: http://www.tracopower.com/products/tmr1.pdf )
    to generate the supply voltage for the following OP-AMP:
    http://cds.linear.com/docs/en/datasheet/1028fb.pdf (The LT1028 CN8)

    My question:
    1. I m connecting the common pin to the "OP Amp - ground" and NOT to the ground of the +24V external supply. I think this should be correct right?
    2. Would it be better to put a ressistance between COMMON and the OP Amp ground? If yes how would you chose it? I got 0 idea.

    Hope you ll be able to help me.
    Cheers and BR
  2. crutschow


    Mar 14, 2008
    1. That is correct.

    2. The input and output are isolated from each other so you can connect the commons together or not as desired. I see no particular reason to add a resistor between the two. As noted in the data sheet, you can connect resistors and capacitors at the inputs and between the input and output as shown, if you are concerned about meeting conducted noise EMI requirements.
    Alex009 likes this.