"Error: Vector [V] not found"

Schematic Simulation (Ngspice)
1

Hi all

I’m trying to simulate a ferrite bead in Kicad+ngspice30 as part of a power supply filter stage. I’m using a Murata spice library that I downloaded from their website, which I’ve copied and pasted below. I’ve set the node sequence in kicad to “1, 2” because the Murata code gives the pins the names “port1” and “port2”.

However, when I try probe pin 2 on the ferrite bead, the spice console gives me the error “Error: vector V(Net-_FB1-Pad2_) not found!” I can probe pin 1, but whatever the circuit is doing, it gives me unity gain and 0 phase shift.

I’ve looked for resources, but documentation on Kicad + spice is scant, and I can’t find any other references to my error on the internet. Can anyone help shed any light on why my simulation isn’t working?

Thanks!

Murata code:

*----------------------------------------------------------------------
* SPICE Model generated by Murata Manufacturing Co., Ltd.
* Copyright(C) Murata Manufacturing Co., Ltd.
* MURATA P/N : BLM21BD272SH1
* Property : Z@100MHz = 2700[ohm]
*----------------------------------------------------------------------
* Applicable Conditions:
*   Frequency Range = 1MHz - 3GHz
*   Temperature = 25 degC
*   DC Bias Current = 0 A
*   Small Signal Operation
*----------------------------------------------------------------------
.SUBCKT BLM21BD272SH1 port1 port2
R1 port1 1 2394
C2 1 2 2.112e-12
L1 port1 2 3.010e-6
R2 2 3 1.308
L2 2 3 1.945e-7
C1 port1 3 1.025e-12
R3 3 4 21.59
L3 3 4 6.984e-8
R4 4 port2 4.500e-1
.ENDS BLM21BD272SH1
*----------------------------------------------------------------------
2

Please post the netlist. To do so, run the simulation. Then do
Tools->Simulation->Show SPICE Netlist

3

Hi, my apologies - here it is:

.title KiCad schematic
.include "C:\Users\hjvl\Documents\KiCad projects\Library\spicelibs\EEETC1V101P\EEETC1V101P.lib"
.include "C:\Users\hjvl\Documents\ferrite.lib"
L1 Net-_L1-Pad1_ Net-_C2-Pad1_ 4u7
V1 Net-_R2-Pad2_ 0 dc 0 ac 1
L2 Net-_L2-Pad1_ out 4u7
R2 Net-_L1-Pad1_ Net-_R2-Pad2_ 0.03R
R4 Net-_L2-Pad1_ Net-_C2-Pad1_ 0.03R
C4 out 0 6u8
XC2 Net-_C2-Pad1_ 0 EEETC1V101P
XFB1 out NC_01 BLM21BD272SH1
.save @l1[i]
.save @v1[i]
.save @l2[i]
.save @r2[i]
.save @r4[i]
.save @c4[i]
.save V(0)
.save V(GND)
.save V(Net-_C2-Pad1_)
.save V(Net-_L1-Pad1_)
.save V(Net-_L2-Pad1_)
.save V(Net-_R2-Pad2_)
.save V(out)
.save V(out_ferrite)
.ac dec 10 1 10000k
.end
4

In the netlist, there is no

Net-_FB1-Pad2_

, but only a

Net-_R2-Pad2_

What is FB1 ? I don’t see it in the netlist, nor in the Murata lib.

5

FB1 is the ferrite bead’s refdes in the schematic. There’s no clear convention what it should be, and the Murata lib doesn’t specify one.

The question is, what should it be?

6

The second port is renamed by eeschema to “not connected”, NC_01. You may add a load resistor between pad2 and ground.

7

Ah that seems to work (sort of, my response is funky but I think that’s the model), thanks!