Unknown parameter (esr)

Schematic Simulation (Ngspice)
1

Hi Folks,

Forgive me, I am new to simulation, but really excited about it, like unit tests for PCB’s I hope.

I’m using KiCad 8.0.3, and have made a basic circuit with a few capacitors and a dc-dc converter. I added spice files for the un-common components, and for the standard things like capacitors and resistors I’m trying to use the built-ins.

For my polarised capacitor (C1) it has a value of 220uF which translates to 0.00022 F in the simulation model. screen. The code looks like:
C NC--0 NC--1 0.00022

However, when I click Tools → Simulate) it parses the models and shows this error in the console window:

Circuit: KiCad schematic
Error on line:
c.xu1.c1 probe_int_probe_int_net-_d2-k__xu1_2_xu1_2 0 470uf esr=0.05 
unknown parameter (esr)

The problem feels like:

  1. I cannot set the “esr” value
  2. Where did it get that 470uf from ? there is nothing in my circuit with that value

Any advice on where this is coming from or how to fix this would be great :slight_smile:

2

Hi Folks,

I found it using grep :slight_smile:

Turns out, the issue was in a spice model I downloaded for the LM2577 chip, it had that line in it:

C1 Vout GND 470uF ESR=0.05

I removed the ESR part and adjusted the 470uF to 680uF to match the output capacitor. It now parses the files without error and runs a simulation.

I have a lot more to learn, but love the way it shows the simulation as n overlay on the schematic, really nice!

3

Ok, try to update to 8.0.7, which fixes hundreds of minor bugs since 8.0.3

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