Expected Behaviour: Frequency analysis using the .ac command should run smoothly.
Actual Behaviour: I get the error of "singular matrix: check nodes 5 and 5" and finally it fails after reducing gmin and reaching the iterations limit.
Steps to reproduce the behaviour
Hello,
I am simulating a simple circuit in python using NgSpiceShared in PySpice (code is attached). When I do a .tran analysis, there is no problem whatsoever. But when I wanna do frequency analysis using .ac, I get the error of "singular matrix: check nodes 5 and 5" and finally it fails after reducing gmin and reaching the iterations limit.
The strange thing is that there is no error in LtSpice when I do this, and even with NgSpice there is no problem in the transient analysis. I wanna know if there is a problem with .ac command or my code.
Any help is very much appreciated.
Code:
import PySpice.Logging.Logging as Logging
logger = Logging.setup_logging()
from PySpice.Spice.NgSpice.Shared import NgSpiceShared
Environment: Python
Expected Behaviour: Frequency analysis using the .ac command should run smoothly.
Actual Behaviour: I get the error of "singular matrix: check nodes 5 and 5" and finally it fails after reducing gmin and reaching the iterations limit.
Steps to reproduce the behaviour
Hello,
I am simulating a simple circuit in python using NgSpiceShared in PySpice (code is attached). When I do a .tran analysis, there is no problem whatsoever. But when I wanna do frequency analysis using .ac, I get the error of "singular matrix: check nodes 5 and 5" and finally it fails after reducing gmin and reaching the iterations limit.
The strange thing is that there is no error in LtSpice when I do this, and even with NgSpice there is no problem in the transient analysis. I wanna know if there is a problem with .ac command or my code.
Any help is very much appreciated.
Code: import PySpice.Logging.Logging as Logging logger = Logging.setup_logging() from PySpice.Spice.NgSpice.Shared import NgSpiceShared
ngspice = NgSpiceShared.new_instance()
circuit = ''' .title Test Circuit
Vinput in 0 dc 0 ac 1 C0 in 1 10560pF ic=0 C1 0 2 10560pF ic=0 C2 1 2 890pF ic=0 L0 1 2 1.08mH ic=0 L1 0 3 1.08mH ic=0 K0 L0 L1 0.45 C3 0 3 890pF ic=0 C4 0 4 10560pF ic=0 C5 3 5 10560pF ic=0 R0 4 5 2KOhm .options filetype = binary .options NOINIT .options TEMP = 25°C .options TNOM = 25°C
.ic v(0)=0 v(1)=0 v(2)=0 v(3)=0 v(4)=0 v(5)=0 .ac lin 10 50k 60K .end ''' print(circuit)
ngspice.load_circuit(circuit) ngspice.run()