Importing lm5156 PSpice model into proteus

[RobinF]

hi i'm trying to convert a pspice model i got from the texas instruments website for lm5156, is this possible? should i create a model request or is the pspice model not useful for creating a prospice compatible model

[Ettore]

I'd try to convert the average model (Unencrypted LM5156x-Q1 PSpice Average Model) rather than the transient one. The reason is that the former is faster and easier to convert (provided you know how to) albeit less accurate, while the latter is slower and strongly tricky to convert to SPICE3 due to strictly PSPICE features used in the original TI model. Just FYI most of the incompatibilities are due to PARAMS:, IF (conditional) and TABLE; the latter is really tricky (if not impossble sometime) to convert.

[RobinF]

thanks , big help. Question that's probably irrelevant but i'm curious and i haven't found any documentation on it. What does the hierarchy module do? I've seen it recommended as a way to make models compatible but i don't understand how or why a sub circuit is created for the part when it's activated

[Ettore]

Yes, you're correct; hierarchy module is another way to make models in a schematic form rather then the usual SPICE language. It works more or less as the LtSpice models modules. When you check it you get the access (with CTRL+C) to a child sheet which is an area where you put the primitive objects in (other spice dialects call them behavioural blocks) that you use to build the equivalent schematic of the device you are going to model. You can then exit to root sheet by pressing keys combination CTRL+X.

The primitives are both digitals and analogues and you can find them all under Pick Devices->Modelling Primitives for the behavioural blocks and Pick Devices->Simulator Primitives for generators and other features.

I'll PM you a simple example of an analogue part with hierarchy module in.