What is self resonance? Have you ever wonder why a lumped prototype performance does not match to the simulated one at certain frequencies? This is due to the effect of the parasitic capacitance/inductance resonating with the ideal inductance/capacitance in a lumped element package. Take an inductor for example, at its resonant frequency, the inductor will response like an open circuit. Usually, self resonance is not taken into the account at the early stage of the lumped design process. Therefore, when the prototype is finally constructed, we will notice discrepancies in performance at high frequency range.
For industrial EDA designs, it is impossible to consider only ideal components when designing a real life application. Therefore, in order to give more information concerning the parasitic capacitance/inductance, components manufacturers will include the self resonance frequency of that particular lumped element in its datasheet. This will help give designers the idea on how to compensate for the expected distortions in their EDA designs as well as decision making when making a purchase for a suitable lumped element prior to the prototyping phase. Manufacturers will also create touchstone files to characterize the overall response of the component in a specific frequency range.
In EDS, we have the ability to import the existing touchstone files for viewing the response of a schematic or a component (Check out our FREE Touchstone Viewer here ).
Today we go a step deeper to explore how can we design our own personal, custom components with its own characteristics in EDS. Lets take an example. Say we want to have a 5 nH Inductor with self resonance parameters as shown in the equivalent circuit. We can construct the schematic in EDS and use a feature called Process Design Kit (PDK) to package the schematic into a component.
After packaging, that component will remain in your personal EDS library for your future use. Just like how we use the preset components in the toolbox, now our newly packaged 5 nH Inductor with self resonance circuit can be used just like any other components.
So now instead of needing to construct the equivalent circuit every time we want to consider a self-resonance inductor, we can simply use the packaged inductor to represent it. In other words, we had successfully created our own custom inductor. The possibility is endless with the help of the PDK feature. Make your designing work exciting, intelligent and easy from today onwards. Cheers!