Lawrence Lile wrote in a different thread, in part:
>There are no stupid questions, especially here on the PIClist.

I hope that's true, Lawrence! I have a feeling the following question
might test your assertion!

Of course everyone knows how to use capacitors for bypass on the
+5V logic supply line, to help counter the spikes caused, e.g., by
TTL logic-level switching. The idea is that the charge stored in the
capacitor is available to smooth out the sudden current drain
caused by nearby chips. Or, equivalently, the capacitor forms a
high-pass filter that shunts high-frequency pulses to ground.

My question (hopefully not stupid, but possibly naive as I am just
a physicist and not an EE) is this: can't the same thing be done
with a series inductor? In that case, energy stored in the
magnetic field of the inductor would be available to resist
attempted changes in the voltage level. It seems to me that this
should work to help clean up a +5V logic power rail, and I believe
this is done with SMPSs. But as much as I see people talking
about bypass capacitors, I don't recall much talk of "bypass
inductors" (or whatever it would be called). Are there good reasons
not to do this, maybe I^2R power dissipated in the inductor?

If this is possible, what rules of thumb might apply to the
values and types of inductors to be used?

Michael V

Thank you for reading my little posting.


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