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Using DS schematic capture with LTSpice

Avatar Posted by big_d at

Hi All,

I'm new to DesignSpark and am in the process of 'plumbing it in' alongside LTSpice.  The manual / help says that DS schematics can export to LTSpice and run a SPICE analysis. The reason I want to do this is to ensure that the schematic I lay out is the same as I've designed; simple if I can run a couple of quick tests to check results tie up with original design. [Habit from being an ex chip designer!!]

Where I've got to:

1. I've managed to enter in a few resistors/capacitors, a voltage source, and run an SPICE simulation from DS schematic. It starts, produces the .OP  (DC) results, and even outputs the AC analysis frequency plot.

2. I then dropped in the classic 4 resistor, 1 transistor(NPN) amplifier with caps on input and output.  I CANNOT get the device model parameters onto the transistor. The help file talks about entering in commands vis the 'values' boxes but I cannot get it to accept the parameters.(e.g. SPICEMODELPARAMETRERS etc)  For now, I'm only trying to use a very limited model (only NPN and Beta = 100; (Bf=100)). 

3. My long term plan is to call opamp models etc into the DS schematic in order to check results before finalising PCB layout. This is a bigger challenge but saves a lot of mucking around if I can get working.

What I really need is either: A). an existing schematic which runs with DS / LTSpice and passes the model parameters; or B). advice / document from somelne who has managed to get the two working together.

Clearly they do work(as I've proved with simple circuit) but model passing instructions are unclear; can someone give me a nudge in the right direction??

best regards,

 

 

 

Replies

  • Avatar

    Posted by MikeBK at

    Hi big_d,

    For the simulation features to work propely everything needs to be configured. You have already realised that. Please use components form the LTSpice library and see the example projects in the LTSpice folder

    The typical folder location for WinXP is C:\Documents and Settings\All Users\Documents\DesignSpark PCB\Examples\LTSpice, for Win7 it will be the analogue location.

    I hope that helps

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