Parameter Passing to Subcircuits

[tomhajjar]

Attached is a project showing how to pass parameters to a sub-circuit/model in Qucs-S/ngspice. There are a few conditions required to get everything to work.

1. The Spice model may need to be modified. If it contains ".PARAMS", .PARAMS must be removed. For the Spice model "VCRES1.lib" the original line was ".SUBCKT VCRES1 1 2 4 5 .PARAMS RVAL=10K" was changed to ".SUBCKT VCRES1 1 2 4 5 RVAL=10K".

2. If you want to alter a Spice model to add User alterable Parameters, change a fixed value like "10k" to "RVAL" and then add RVAL=10K. See "VCRES1.lib".

3. When making a subcircuit schematic with User alterable parameters, you must put the PARAMS info in BOTH the schematic AND symbol sections of the subcircuit schematic. See "74HCU04_lib.sch", "genericopa_sub.sch" and "VRES1.sch".

Parameter_Passing_prj.zip