ADA4528-2 driving current

Hi,

I'm using ADA45-28-2 opamp as an unity-gain buffer to drive a sensor bridge. so it's very important to me that the output of ADA4528-2 doesn't change with the load current change.

(in my case the load is resistive and current changes slightly around 5ma working point).

I've already tested the ADA4528-2 with the gain > 1 and saw that the voltage will respond to the current variation by a reduction in output voltage (as I expected based on the datasheet).

Does ADA4528-2 shows the same behaviour also in unity-gain configuration as it does for higher gains values?

If yes can you please tell me how much it is? 

Best Regards

  • Hi 

    I think that I got my answer from datasheet. 
    It would be very kind if you can tell me it is correct or not.

    I can use it from the "Output Voltage (VOL) to Supply Rail vs. Load Current" plot. So I can calculate the output voltage allowable swing for various load currents and different supply voltage.
    Based on my understanding this is not related to the Gain values. Gain values makes the output voltage higher and closer to the supply rail.

    Thank you

    Regards

  • 0
    •  Analog Employees 
    on May 31, 2021 1:35 AM in reply to mehdiaghayi

    Hi,

    You're correct, the Output Voltage to Supply Rail vs Load Current will guide you in calculating and knowing how much allowable output voltage you can achieve based on your load current.

    You could relate this to Gain, because the gain would be the scaling factor for you to achieve the necessary output voltage swing.

    Thanks,

    Donnie