Este mensaje contiene elementos interactivos.
# magic
j
Este mensaje contiene elementos interactivos.
t
There is a general interface for devices that are generated from an exact layout provided by the foundry; that interface allows devices to be arrayed in X and Y. This would not be particularly useful for inductors, but I didn't bother to create a separate GUI dialog for inductors. Inductors 1, 2, and 3 are inductors of different sizes provided by the foundry. However please be aware that those devices belong to an old variant of the original S8 process which had 3 metal layers with a very thick top metal good for making inductors. The metal 3 inductor layout is not ideal in the existing sky130 process, where metal 3 is not a thick metal and has additional metal layers on top. It would be more appropriate to use metal 5 for inductors on this process. But also, the circuit model for this device will be completely wrong for the sky130 process. Generating an inductor of any size can be done but I have not written any scripts to automate the process (mainly due to a lack of any device models).
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j
so what is the recommendation to make coils in this technology?
t
Use an inductance solver like FastHenry to estimate the inductance of a coil layout, and make sure your design has room for plenty of margin in the inductance, because most likely it won't be very accurate.
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The other choice is to find projects from the first few MPW runs that had inductors on them, and see if any of the designers have measured the devices to get a simple device model.
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j
Is a tool open source?
t
FastHenry is open-source (see https://www.fastfieldsolvers.com).
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j
Thanks thanks, is it not necessary to have anything from the pdk to make the inductors? how magic or klayout which requires pdk files? (information on metals etc)
t
It needs to satisfy design rules, is all. Magic has commands like
wire segment
that you can use to draw the inductor without too much hassle. Klayout has some implementation of the GDS PATH record that will do the same thing.
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j
hello @Tim Edwards, is this tool also used to design coils with sky130A? or what other alternatives are there?
t
You're probably best off asking people in #analog-design about who has made inductor designs and how they did the inductor layout and analysis. I have used FastHenry for transmission line analysis a long time ago, and I know that it can analyze metal geometry and estimate the inductance, but I have not used it to design an inductor, and I don't know if it can accurately model the dielectric stackup of the sky130 process (FasterCap can, though, and I think both programs may use the same or similar input file format).
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