ngspice in KiCad 8: Creating a (digital) subcircuit model for a multipart device (74HC10)

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  • Опубліковано 3 гру 2024

КОМЕНТАРІ • 6

  • @HansWurst-bk9sb
    @HansWurst-bk9sb 7 місяців тому

    Hi Holger, how to convert the inputs and outputs of the digital parts then into near-real-life values with input thresholds and output voltages? Is there a handy mechanism for then transition into analog simulation again?

  • @HUEHUEUHEPony
    @HUEHUEUHEPony 9 місяців тому

    Another question that is less offtopic, how does the models know where ground and power is since you never defined it?, I know that they dont need it, but still, how do they know?, how can they tell that I plugged 7 or 14 at the right place?

    • @holger8105
      @holger8105  9 місяців тому

      They don't make use of 7 and 14, they don't need it, as internally it is a fast 1 and 0 event based logic simulation, like in a logic simulator.

  • @HUEHUEUHEPony
    @HUEHUEUHEPony 9 місяців тому

    dumb question, is it possible for me to edit the schematic of a symbol or footprint, then I could theoretically do the AND gate with nmos and pmos myself and just copy paste from there. Then I would have the subcircuit schematic and simulation of whichever model I wanted.
    The reason why I ask this is because I wanted to simulate the cd4081 in kicad, but it seems everywhere I look the spice syntax is not compatible with ngspice leaving me with a lot of frustration.
    Also the naming is confusing 74HC10 is not really a 74HC10 but a NAND(3) gate, they could just mention that instead of false advertising they have the complete package. And that is work to the reader.

    • @holger8105
      @holger8105  9 місяців тому

      Please have a look at forum.kicad.info/t/how-do-i-simulate-a-74ls74-flipflop-using-ngspice-41/45571/11 how to find a model for the 4081.

    • @holger8105
      @holger8105  9 місяців тому

      All these models for other simulators are compatible to ngspice, but not to KiCad/ngspice, as KiCad/ngspice is the only simulator which simulates complete packaged ICs. All the others simulate individual gates, and you may place as many as you like. In KiCad/ngspice the symbol rules, as the whole business stems from PCB design.
      If you have done your model for your symbol, you may publish it, to help others, and so some day we have all relevant symbol/model combinations available.