AD5520:trouble with MEASOUT voltage range

HI this is my sch of ad5520. the pin 64(CLL) vee_3v3 is -3.3V and pin 63(CLH) vcc_3v3 is +3.3v.

I change the pin 26(FIN) voltage , the pin 58 (MEASOUT) should from -3.3V to + 3.3V . but the pin 58 (MEASOUT)  is -0.256V to 3.3V.

the R74 is 100K. and in force current mode

why the pin 58 (MEASOUT)  is -0.256V to 3.3V.

  • Hi,

    I moved this query to this community. Someone here should be able to help you.

    Regards,

    Mark

  • Hi yuanyang,

         Unfortunately, I cannot address your problem if I dont have a more complete detail on your schematic.

    1. Can you please place the values for your DVDD, AVCC and AVEE.
    2. What Current Range are you on?(i.e. Logics on the AMx pins and QMx pins)
    3. Logic of FSELx (I assume this is High for Force Current Mode.)
    4. Logic of MSELx?
    5. What is the voltage range on the Vfin during FI Mode?
    6. Lastly, what is your end application for this circuit?


         I am looking into this already. Answering the questions above can resolve the issue more quickly.


    Thanks,

    Tom