LTspice: Combining Multiple Model Instances Into One Symbol

When you need multiple instances of a model, it is easy to copy and paste a symbol, but sometimes you can tighten up your schematics by using a single symbol to define multiple instances of same device. For instance, instead of placing four identical capacitor symbols in parallel, use one symbol times four, “x4”. This feat can be accomplished using the M (parallel units) or N (series units) parameters.

Component Editor

Component Editor

A number of intrinsic devices support the M (parallel units) parameter, such as the capacitor, inductor, diode and MOSFET models. If you are not sure if the model supports the M (parallel units) parameter, try it, and if you do not get an error message, you should be good. The diode (including LED) model is the only intrinsic model that supports N (series units) parameter.

To define multiple instances of a model in a device symbol:

  1. Ctrl + right-click the symbol to edit the component attributes.
  2. Insert “m=<number>” or “n=<number>” into the Value2 field. Note that non-integer <number> values are allowed.
  3. Make the multiple instances visible in your schematic by selecting the Value2 attribute and clicking the Vis column.

Parallel Capacitors

To match certain electrical schematic standards you can define parallel capacitors either using “m=<number>” or “x<number>” syntax as in “x4”.

Parallel Capacitors

Parallel Capacitors

Series (String) of LEDs

Diodes are the only intrinsic models that support the N (series units) parameter.

LED String

LED String

Об авторах

Gabino-Alonso

Gabino Alonso

Gabino Alonso is currently the director of strategic marketing for the Power by Linear™ Group. Prior to joining ADI, Gabino held various positions in marketing, engineering, operations, and education at Linear Technology, Texas Instruments, and California Polytechnic State University. He holds a Master of Science degree in electrical and computer engineering from University of California, Santa Barbara.