This is an attempt at making a universal filter for the excellent SPICE software that is
LTspice. A filter that can be both analog and digital, which can be configured to be either all-pass, low-pass, high-pass, band-pass or band-stop. A filter that can replace the slow process of calculating, implementing and then using a (multiple stage) filter, when the purpose of the simulation is different, not to mention the need to repeat the steps whenever changes occur. A filter that can be used anywhere a filtering function is needed, be it a quick example or a full-scale schematic, that's simple to use and reliable.
The result is
filter.sub, the library holding the subcircuits, accompanied by its symbol,
Filter.asy, made available under the
GPL license. When browsing the
.sub
file (or any other
SPICE
library, model or netlist, for that matter), if
Linux/UNIX is the environment used and if
gEdit, or any other text editor using
GtkSourceView (like
Scribes or
Mousepad) is the editor of choice, a useful tool can be this
SPICE
language file and, optional, the
color settings, matching LTspice's.