Using DS schematic capture with LTSpice
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,
