Post Go back to editing

AC analysis of transimpedance amplifier LT-SPICE


I am working on a design that requires integrating transimpedance amplifier. I have already designed the board but I am having serious issues with the oscillations. 

I would like to simulate my circuit in LT-SPICE & observe the effects of various capacitance that I have added around this opamp on its stability. I am new to LT spice and have only gone through some online available beginner tutorials to get my self familiarised with the environment.

Could someone please guide me (share some links) where I could find some help to simulate a transimpedance amplifier to AC transfer characteristics (BODE plot to check the stability)

I am using AD8603 & AD8607 opamps for this circuit.

The circuit is part of integrating an electrochemical sensor with bias.So other half of circuitry is a potentiostatic & I am not sure if I could simulate that circuit!? 

Also, I understand that circuit needs to know the capcitance of my sensor that goes at the input of transimpedance amplifier. Are there any models for electrochemical sensors? The datasheet of the sensor that I am using gives no information about its internal capacitance. Is there anyother way to gauge it?

Any help would be greatly appreciated

  • Hi,

    You can start your design using the Analog Devices web tool called Photodiode Wizard.

    In the photodiode wizard tool, you can input the needed specs from your photodiode such as the junction capacitance and peak current on the tool.

    The tool will then let you input your required peak voltage, speed and the will suggest the appropriate amplifier based on the specs you provided.

    You can see Pulse response, Frequency response and Noise as you adjust your inputs.

    Finally, when your done in your TIA design, you can export a LTspice ckt version of your design.

    Here is a link of basic tutorial of Photodiode wizard tool.

    Hope this helps.