Passing Parameters to Hierarchical Block in LTSPICE

There were a couple of questions on how to pass parameters to Hierarchical Blocks from main level schematic in LTSPICE. In fact, until recently, I was having troubles doing this. But solution is very simple and strait forward. Read more

Subsircuit analisys, converting subcircuit netlist to schematic

Imagine, you are lucky to get subcircuit for component you’d like to simulate. How good this subcircuit is?

Quality of simulation strongly depends on quality of subcircuit model that is used. Unfortunately, netlist for complicated subcircuit does not look like schematic drawing and is hard to interpret. Yes, everything is there, but as many design engineers, I’m thinking in terms of schematic when it is comes to necessity of interpreting functional behavior. Read more

Hierarchical Blocks in LTSPICE

LTSPICE is offering very nice possibility to incorporate repeatable portions of schematic into simulation, that is not available in many other SPICE simulation programs- hierarchical blocks. Hierarchical blocks represent reusable portions of schematic, visible on higher level of schematic as a symbol. While LTSPICE is missing multipage schematic editor, hierarchical blocks are offering another simple way of creating complex schematics. Read more

Schematic Integration of Subcircuit into LTSPICE

LTSPICE is offering very simple and straight forward way to create a symbol and  connect it to subcircuit definition.

Every subcircuit that you want to use should have corresponding schematic symbol. Symbol is a drawing, used to represent a device, described by a subcircuit or a hierarchical block. You may use existing symbol if it’s pinout and functional drawing corresponds to your subcircuit, or you may create a new drawing to represent unique subcircuit definition that you just created. Read more

Subcircuits in LTSPICE

Your simulation is as good as quality of the models you are using!

At least it is no better than that. This is the reason why I would like to dig into LTSPICE Subcircuit topic and create a simple reference. I’m using it myself and hope it will save you some time also. Though, there is nothing new in this tutorial and most information is just recollection of different parts of LTSPICE and SPICE3 documentation. Read more

Subcircuit structure

  1. Header
  2. Netlist
  3. End

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