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Pspice Model editor commands and capabilities.

AndyK1

Hello,

My name is Andy and I am currently working as an intern. At my jobsite, we have OrCad 16.5 avalible to us. I am trying to use the model editor for pspice to create parts that will have the actual worst case data behind them.

As an example, a milspec resistor may have %1 tolerance on its own, but this number increases with respect to the enviroment, how hot it is, radiation, life time of the part etc.. When everything is said and done, this number maybe 1.82%. I want to create a part that would have the proper part name and the tolerance on it so when a reliability engineer wants to run worst case analysis on pspice, he or she can directly pick the part from the library and place it on the circuit. I am also planning on automating the system of generating these parts and do it for thousands of different parts. The parts range from simple resistors all the way to transistors, even some stuff that has their own sub circuits like an LM117 voltage regulator.

My question is what type of commands am I allowed to use inside the model editor? I will be more than likely creating these files by exporting excel data in to text. Can I use functions? Are there ways of doing mathmetical calculations inside the model such as " dev=(R1*.01)%" or use Value statement etc..

Where can I get a hold of the complete valid command list for pspice models and subcircuits?

I may need to used add,subtract, exponent,min(),max(),log type functions. Can pspice models handle these functions?

  • oldmouldy

    Take a look at the pspcref.pdf, in the doc\pspcref directory of the installation, this is the reference for the PSpice models and model syntax.

  • AndyK1
    I am looking at the Pspice model of an LM117 Voltage regulator and I cannot decipher these lines of code. That document that you linked does not have any explanation on the  EFB, EB and EP type devices.

    ESC 11 OUT VALUE(5.646-0.1125*V(6,5)*V(13,5)

    EFB 12 OUT VALUE {7.886-0.3727*V(13,5)+0.005097*V(13,5)*V(13,5)-0.02*V(13,5)*V(6,5)} . E

    EB 7 OUT 8 OUT 7.691

    EP 9 OUT 4 OUT 100
  • oldmouldy
    Only the first character counts for a PSpice model, look at Analog Parts in the reference, these are all E parts, voltage controlled voltage sources.
  • AndyK1

    Thank you that did work. What is going on with the E models with only 2 parameters and the "Value" statement? 

    Does that calculate the voltage that should appear between those two nodes, instead of physically connecting them to a source?

    Is this the only place to use Value? Actually what does the Value statement do?  

  • Alok Tripathi

    refer the following syntax

    ESQROOT 5 0 VALUE = {5V*SQRT(V(3,2))}

    This statement in circuit file would simulate a voltage source between node 5 and ground (0), whose value is function of voltage between Node 3 and 2 [V(3,2)] (5 times value of voltage between node 3 and 2.

    HTH

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