Hello All, I was wondering if anyone had any suggestions on where to look for doing Analog Behavioral Simulations with open source tools. I would ideally be running Verilog-A along side spice models however my understanding is that this is not currently possible using open source tools. Another option would be to build what would be the Verilog-A model using only spice with Xschem, in this case does Xschem support creating an equation controlled source and does NGSpice support simulating one? I would also be interested in trying Xyce if NGSpice doesn't support this, but I have not had good luck with Xyce and sky130 in general. Something like the BI and BV functions in LTSpice? Thank you all for any help you can provide!

ngspice supports Verilog-A, but it is very cumbersome, as the Verilog-A model has to be compiled into the ngspice executable. It would be nice if the models could be run-time loadable. But it is doable (in theory---I've never tried it).

@Tim Edwards Excellent! I will look into that. Thank you for the help!

@Bryce Readyhough: If you figure out how to do it, I'd like to know. . .

Is that using the ADMS plugin? If so it probably isn't much good for want you want to use it for. It's pretty sketchy and although technically it's verilog-a it's not really the same as when you use verilog-a in spectre for example. A lot of the useful quasi-digital functions that are useful for behavioural modelling is not supported. The xyce team are quite clear about its use in xyce: its acceptable for describing differential equation based device models. It's not much use at all for something like a simple behavioural model of a comparator

@Bryce Readyhough ngspice does support B primitives. I use them for modeling the nonlinear behavior of opamps with railed outputs for example with the tanh() function.