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AD8397 : Clarification regarding output swing range

Category: Datasheet/Specs
Product Number: AD8397

Hi Analog, I hope you are having a pleasant day !!

Description of the issue:

The reason I am here is to get some clarification regarding the output swing range of AD8397 full-swing Opamp. I have simulated a simple Voltage follower circuit in LTspice to check the maximum and minimum Voltage at the output. Below mentioned are the configuration and observations made.

  1.  I have used "ad8397.cir " model for simulation. I got this model from the product info page of AD8397
  2. Supply of +5V and - 5V are given to VCC and VEE respectively
  3. Input is a 1000Hz sine wave with 0 DC offset and 10VPP
  4. During the positive half cycle the output clips at 4.57 V
  5. During the negative half cycle the output clips at -3.64 V

Query:

  1. In datasheet, it is mentioned "Output swing to within 0.5 V of supply rails"
  2. But in simulation the observations made were different.
  3. Please let me know if the simulation result is wrong Or if is there something more I need to know.
  4. I have attached screenshots of the simulation result for your reference.

Thanks,

Sameep Pai K S



Added product number and category
[edited by: GenevaCooper at 2:03 PM (GMT -5) on 10 Feb 2023]

Top Replies

    •  Analog Employees 
    Mar 5, 2023 in reply to ZoltanDTI +1 verified

    Hello ,

    I have run some tests in the lab using your setup and here are the results:

    Dual Supply: Vs = +/- 5 V

    Input = 1kHz, 10Vpp

     

    Output:

     

    Single Supply: Vs = + 5 V

    Input = 1kHz, 5Vpp, 2.5 V…

Parents
  • Hello  ,

    I have also observed the same results when I have used the spice model in my simulations:


    This is indeed a questionable behavior. I will be verifying this output using an actual setup in the lab through bench testing. This will help us identify whether or not there is a problem on the spice model. 


    Kind Regards,
    Paul

Reply
  • Hello  ,

    I have also observed the same results when I have used the spice model in my simulations:


    This is indeed a questionable behavior. I will be verifying this output using an actual setup in the lab through bench testing. This will help us identify whether or not there is a problem on the spice model. 


    Kind Regards,
    Paul

Children
  • Hi Paul,

    1. Thanks for acknowledging the problem. Can you please let us know about the bench test reports?
    2. Can VCC and VEE be provided with different voltages?(Example :VCC=12V and VEE = -5V).
      1. If Yes, would this configuration have any long-term reliability issues?
    3. Additionally, if possible, could you provide a snippet of the outputs from your bench testing for
      1. VCC=5V and VEE =GND
      2. VCC=12V and VEE =GND
      3. VCC=5V and VEE =-5V
      4. VCC=12V and VEE =-12V
      5. Note: Please supply an appropriate input for the above-mentioned voltages so that clipping may be accurately noticed

    I appreciate your quick response


    Regards,

    Sameep Pai K S