• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 342 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV2700: DRV2700

Thomas J Miller
Prodigy 10 points
Part Number: DRV2700

I am using the DRV2700 (3) to drive a piezo micropump.  We have an asymetrical bipolar outputs (i.e., +100V open, -50V closed).  IN- input is biased at one half the DAC reference voltage (2.5V) driving IN+, so the midpoint is 1.25V.  However we see different offsets on IN- from 1.29 to 138V which means we cannot get accurate drive from out ADC with an asymetric input signal.

  • 0
    TI__Genius 13610 points

    Hello Thomas,

    I am going to need more details in regard to what are you putting gain at and could you be more clear what is the voltage on each input pin when you are getting the 138V output.

    Thanks,

    Carson

    LPA Application Engineer

  • 0 in reply to Carson Allen
    TI__Genius 13610 points

    As well as what is your boost voltage at?

  • 0 in reply to Carson Allen
    Prodigy 10 points

    You misunderstand.  If you look at page 4 you can see how we are driving the first channel.  We are using a variety of boost voltages; 55, 80 and 105.  We are applying asymmetrical drive signals for outputs like +100/-50 (DAC 2.5/.625 respectively).  The IN- is biased at half the 2.5V reference used by the DAC that drives IN+.  The circuit works, but there is an error that I think is related to the actual IN- voltage which should be 1.25V but has been measured anywhere from 1.29 to 1.38V.  This creates an imbalance in the output relative to the driving DAC signal.

     

    Tried to reply with a schematic (2MB) but was rejected.  Please email me and I will send the information you requested (need to send attachemtn).

  • 0 in reply to Thomas J Miller
    TI__Genius 13610 points

    I will send friend request on E2E for further discussion and to provide my email