Error with CN0381

I think there is a mistake in design CN0381 with the IOV_DD voltage regulator. The ADJ resistor pair for the ADP1720ARMZ-R7 is shows R1=57.6k and R2=27k. If I am reading ADP1720.pdf page 10 correctly, this produces a voltage of 3.8V instead of the desired 1.8V.

This would also exceed the IOV_DD to GND spec of max=3.6V on page 94 of ad7124-8.pdf.

Swapping them around would solve the problem.



  • 0
    •  Analog Employees 
    on Sep 7, 2020 6:27 AM 2 months ago

    Hi Eric,

    Apologies, this is a mistake in the block diagram representation. You are correct in both that the resistors should be swapped and that this would violate the AD7124 abs max specs.

    The schematic has them in the correct positions. R1 = 27k and R2 = 57.6k. You can get the schematic from the Design Support Files.