Best DAC interface to circuitry

Discussion in 'General Electronics Chat' started by fsonnichsen, Nov 26, 2013.

  1. fsonnichsen

    Thread Starter New Member

    Jun 6, 2013
    15
    0
    I am confronted with interfacing separate DAC outputs of a PIC to 1M and 100K impedance inputs on other devices. This is a DC system. I need the full swing of 0V to 3V. Also I would like a single supply here-I have a 0/5V system. I am leery of direct connection to the PIC-it is advised against by Microchip.

    An ordinary single supply opamp or BJT source follower won't don't here due to the offset floor. Maybe a rail to rail op/amp would do.
    How about a matched pair FET-I think that gives no offset yes?

    Wondered how others solve this problem-any comments appreciated-

    fritz
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,002
    3,231
    Best would likely be a good rail-rail op amp in a non-inverting follower configuration. With a 5V supply they will go from essentially 0V to a full 3V output.

    Matched-pair FETs are not likely a good choice for this.
     
  3. fsonnichsen

    Thread Starter New Member

    Jun 6, 2013
    15
    0
    Thanks for the reply. I ordered a few TLV2772AIP amps a few days ago and was hoping to test them soon. I think these comply with your advice.

    cheers
    Fritz
     
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