SPICE Circuit Parameter Extraction

[py_engineer]

Hi,

I am looking for information on how to extract circuit parameters.

I have a system, and I can experimentally perform current and voltage measurements. For example, I can measure the voltage response of the system as a function of a given input pulse.

In addition, I also have an equivalent circuit model to represent this system, composed of various resistors and capacitors.

What I don't know is the resistance and capacitance values for the elements in my equivalent circuit model.

I was wondering if there are tools, like SPICE tools, or methods to extract the circuit parameters that would fit the best my experimental data. I have a SPICE extraction tool, however it is designed to extract transistor parameters. I can't find tools that can extract general circuit parameters. I am not sure that I am being very clear, so please let me know if this is confusing, and if you have suggestions on tools and methods.

Thanks a lot!

 

[Kholdstare]

If your circuit is all passive, you can get equivalent circuit components by measuring resistance and inductance/capacitance.

 

[py_engineer]

Hi,

Thanks for your answer. My system is a black box, so I can't just go and measure the resistances and capacitances. I have an equivalent circuit model for my system, and I can obtain experimental data from the system, so I am just looking for a tool that will fit the equivalent circuit model to the experimental data.

 

[Kholdstare]

If you have experimental data, then you can use Matlab/Origin etc. to curve fit on the data using a custom defined curve. If you want to fit it in SPICE model the work is same. However, you have to know the SPICE model equations which will be used for fitting.

 

[alphysicist]

Hello,

Thank you for reaching out about your question on SPICE circuit parameter extraction. There are indeed tools and methods that can help you extract circuit parameters from your experimental data and equivalent circuit model.

One method is called curve fitting, where you can use software such as MATLAB or Python to fit your experimental data to your equivalent circuit model and extract the parameters that best fit the data. Another method is called optimization, where you can use software such as SPICE or LTSPICE to optimize the circuit parameters to match your experimental data.

In addition to these methods, there are also specific tools designed for circuit parameter extraction, such as Keysight's IC-CAP software. This tool allows you to extract general circuit parameters from your experimental data and equivalent circuit model.

I hope this helps answer your question and provides some options for you to consider. Let me know if you have any further questions or need additional clarification.

Best,