Limits the absolute value of current flow between b and b to Imax with a small series resistance and reverse current from a behavioral current source:

                  +-------+
       a >---+--->| shunt |>----------- 1 -- Rs ---+--------> b
             |    +-------+                        |
             |        |                            |
             |        x                            |
             |    +-------+                        |
             |    | H:Lpf |>-- 2 -- R --+-- C --+  |
             |    +-------+             |       |  |
             ^                          3       0  V
             |                          |          |
             |                          x          |
             |                      +--------+     |
             +---------------------<| B:Irev |<----+
                                    +--------+

This is a bidirectional limiter; it develops voltage drop to counteract current flow approaching the limit regardless of what direction the current is flowing. Viewing the subcircuit from the outside, it appears that the series resistance Rs increases drastically as the current approaches the limit.

The series resistance Rs is calculated based on Imax and Vmin. Lower values of Vmin result in a lower Rs and a sharper cutoff at the current limit. The "knee" voltage transitioning from linear to current-limited behavior is approximately equal to Vmin.

When ts is set, the CCVS with RC LPF on its output is included for SCA. Without it (at least as observed in unidirectional mode), the behavioral source sometimes oscillates in an effort to limit current that is very close to zero.

Instance Variable	Imax	The current limit in Amperes.
Instance Variable	Vmin	The minimum voltage that the limiter is expected to drop at the current limit. Default: 0.5 V.
Instance Variable	n	The exponent used in the saturation equation. A higher exponent means sharper, more drastic limiting. Default: 2.0
Instance Variable	uni	Set `True` to use a unidirectional current limiter, which is more reliable given Ngspice's habit of messing up operating point with B-sources. When set, current is only limited if it flows from 'a' to 'b'. (type: bool)
Instance Variable	reverse	Set `True` to use unidirectional current limiting with current flowing from 'b' to 'a'. Sets uni. (type: bool)
Method	setup	Subcircuit definition.

Inherited from NodeStuff (via Subcircuit):

Instance Variable	shunts	A dict of current sensing V elements with the pairs of nodes they connect.
Class Variable	debug	A `Bag` that gets set `True` for all instances to log info about each `setup` call.
Class Method	autoName	Undocumented
Method	setupResults	Undocumented
Method	fill	Undocumented
Method	nodeCheck	Call with the circuit building tool f and a sequence of nodes provided to this `Include` or `Subcircuit`.
Method	rawNetlist	Get lines of a raw netlist from a search hierarchy of possible sources.
Method	shunt	Call to insert a current-measuring shunt and add an entry to my `Elements` baton's dict of shunts.
Method	raw	See `Elements.raw`.
Method	iNode	See `Elements.iNode`.
Method	ground	See `Elements.ground`.
Method	sca	See `Elements.sca`.
Method	sca6	See `Elements.sca6`.
Class Method	_libDir	Undocumented
Method	_strippedLines	Undocumented
Method	_call_setup	Calls my `setup` method (almost always your override of that method, actually) and processes any return value.

Inherited from NodeStuff (via Subcircuit):

Instance Variable	shunts	A dict of current sensing V elements with the pairs of nodes they connect.
Class Variable	debug	A `Bag` that gets set `True` for all instances to log info about each `setup` call.
Class Method	autoName	Undocumented
Method	setupResults	Undocumented
Method	fill	Undocumented
Method	nodeCheck	Call with the circuit building tool f and a sequence of nodes provided to this `Include` or `Subcircuit`.
Method	rawNetlist	Get lines of a raw netlist from a search hierarchy of possible sources.
Method	shunt	Call to insert a current-measuring shunt and add an entry to my `Elements` baton's dict of shunts.
Method	raw	See `Elements.raw`.
Method	iNode	See `Elements.iNode`.
Method	ground	See `Elements.ground`.
Method	sca	See `Elements.sca`.
Method	sca6	See `Elements.sca6`.
Class Method	_libDir	Undocumented
Method	_strippedLines	Undocumented
Method	_call_setup	Calls my `setup` method (almost always your override of that method, actually) and processes any return value.

Imax =

The current limit in Amperes.

Vmin =

The minimum voltage that the limiter is expected to drop at the current limit. Default: 0.5 V.

n =

The exponent used in the saturation equation. A higher exponent means sharper, more drastic limiting. Default: 2.0

uni =

Set True to use a unidirectional current limiter, which is more reliable given Ngspice's habit of messing up operating point with B-sources. When set, current is only limited if it flows from 'a' to 'b'. (type: bool)

reverse =

Set True to use unidirectional current limiting with current flowing from 'b' to 'a'. Sets uni. (type: bool)

def setup(self, f):

overrides pingspice.circuit.netlist.Subcircuit.setup

Subcircuit definition.

Why use f? Because it's short and a conveniently typed letter on the keyboard.

Override this if your subclass does not reference a param.ParameterFinder subclass via the Finder class attribute. As with Include.setup, your override method can return a dict of attribute names and values to set in my instance.

API Documentation for pingspice, generated by pydoctor at 2021-09-18 08:41:11.

pingspice.lib.current.CurrentLimiter(Subcircuit) class documentation

`pingspice.lib.current.CurrentLimiter(Subcircuit)` class documentation