Gain setting in AD8216

Hi

I've selected AD8216 for my design. Is there any possibility that i can set 1V/1V gain in AD8216. How can I do that?

Regards

Nidhi P Shetty

Parents
  • 0
    •  Analog Employees 
    on Jan 20, 2020 1:34 AM

    Hi Nidhi, 

    I would echo what Kirill has said. The internal resistor ratios of the AD8216 have been trimmed for high precision, and changing up the gain network could severely degrade the accuracy of the device. 

    Could you give me more information about your application? Perhaps we can find a better amplifier for you. We do have a couple of other difference amplifiers that can be configured in a gain of 1, like the AD8276. What input common mode range does your amplifier need to accept?

    Thanks, 

    Kris

  • Hi Kris

    I'm using AD5420 and AD5421 in my design.(for 4-20mA current output configuration)

    For self diagnosis purpose I need to sense current from these DAC which I'm performing as mentioned below.

    1. In AD5420 sensing is done between it's R3 sense and BOOST pin.

    2. In AD5421 sensing is done between it's LOOP- and COM pin.

    If we check internal architecture of both AD5420 is with high side sense resistor, higher common mode voltage and voltage will be positive

    But AD5421 is with low side sense resistor and  and voltage will be negative.

    Hence I need an optimistic solution (Self Diagnosis ADC) to sense current through these pins and process it

    Regards

    Nidhi P Shetty

  • 0
    •  Analog Employees 
    on Jan 23, 2020 3:22 AM in reply to nidhi.shetty@iwavesystems.com

    Hi Nidhi, 

    I would recommend you check out the LT6375. It is a difference amplifier that can be used for current sensing, which has a wide input common mode voltage range (accepts both positive and negative voltages). It can also be configured in a gain of 1, so it should be a good fit for your application. 

    Let me know if this works for you. 

    Thanks, 

    Kris

  • Hi Kris.

    I've used LTspice XVII to understand LT6375 functionality. With the schematic that I've drawn I'm getting expected output.
    But I wanted know whether my understanding is correct. That i, whether schematic representation for AD5420 and AD5421 sense output / LT6375 input (highlighted in Blue) is correct?

    Snapshots for schematic and plot files is attached.

    Please confirm whether my understanding on schematics what I have drawn is correct.

    Regards

    Nidhi P Shetty

Reply
  • Hi Kris.

    I've used LTspice XVII to understand LT6375 functionality. With the schematic that I've drawn I'm getting expected output.
    But I wanted know whether my understanding is correct. That i, whether schematic representation for AD5420 and AD5421 sense output / LT6375 input (highlighted in Blue) is correct?

    Snapshots for schematic and plot files is attached.

    Please confirm whether my understanding on schematics what I have drawn is correct.

    Regards

    Nidhi P Shetty

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