ADA4522 clamp circuit and

I have two questions about ADA4522

1. For sure.  Amplifier have input EMI filter and clamp circuit with limit the input current to ±10 mA

Should not be a problem with the situation shown in Figure?

 

2. ADA4522 have Input Bias Current 50 -150pA, 50pA make on 200k resistor drop 10uV ,

If I short V3 (left side resistors) the output voltage of AD4522 will be Voltage drop on R1+R2 (Input Bias Current) + Input voltage offset

If I measure the voltage at the output ADA4522 with short V3, for example 20uV and consequently the voltage at treal V3  (for example 1020uV) It is possible to sum of these two measurements to compensate the error amplifier ?

 

  • 0
    •  Analog Employees 
    on Mar 8, 2016 4:26 PM

    Hi Karel,

    With regards to your questions, here's my answer for you.

    1. Yes, this configuration will not damage the device but it will increase the offset voltage due to the imbalance source impedance of the ADA4522.

    2. Can you elaborate what are you trying to do here? Do you want to calibrate the ADA4522 using two point measurements? I believe one time measurement (Short the V3) is enough to know the overall offset voltage on the ADA4522. It would be helpful if you could provide additional details of your applications i.e what are you trying to achieve?, What is the expected input?,  What is the expected output?, etc. so that we could look more into it.

    Best regards,

    Emman

  • 0
    •  Analog Employees 
    on Mar 9, 2016 9:51 PM

    I just wanted to point out that your 100kΩ resistors are each dissipating 2.5W. You might have to go with through-hole resistors to get that kind of power and resistance value combination and it will still generate a significant amount of heat. With voltages this high, there also may be relevant regulatory standards for safety isolation, such as IEC61010-1 or similar depending on the type of equipment.

    Best regards,

    Scott

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:23 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin