tanh gain limit tanh args
Defines a hyperbolic tangent, or soft limiting, transfer function.
There is no corresponding capability in any SPICE that I know of, but you can get close with POLY.
For capacitors, this function defines charge as a function of voltage. For inductors, it defines flux as a function of current.
For fixed sources, it defines voltage or current as a function of time, which is probably not useful.
This function describes a hyperbolic tangent transfer function similar to what you get with a single stage push-pull amplifier, or a simple CMOS inverter acting as an amplifier.
| gain | The small signal gain at 0 bias. (Required) |
| limit | Maximum output value (soft clipping). (Required) |
This function does not directly participate in time step control, except as the device would otherwise. This is considered to be a deficiency, and may be addressed in the future.
E1 (2 0 1 0) tanh gain=-10 limit=2 ioffset=2.5 ooffset=2.5
This gain block has a small signal gain of -10. The input is centered around 2.5 volts. The output is also centered at 2.5 volts. It “clips” softly at 2 volts above and below the output center, or at .5 volts (2.5 - 2) and 4.5 volts (2.5 + 2).