Contents
What do you need to know about Ngspice?
As shown in Fig. 1, you start with a circuit (here: an inverter). You have to create a netlist describing this circuit. The netlist is the input to ngspice, telling it about the circuit to be simulated. Together with some simulation commands this input cares for reading and parsing the netlist, starting the simulation and plotting the output.
Where do I find the voltage source in Ngspice?
The voltage source is connected between 0 (ground) and node ‘in’, value 1, R1 between ‘in’ and ‘out’ with value 1k, R2 between ‘out’ and ground and value 2k. Line 1 is a title line. .end in line 5 denotes the end of the netlist. Put these lines into a text file named vdiv.cir and save it to the folder C:\\Spice64\\bin (If you are with MS Windows).
How to start a simulation in ngspice.exe?
Now start ngspice by double click onto ngspice.exe in C:\\Spice64\\bin. Load the netlist into ngspice by entering the command source vdiv.cir . ngspice is now ready for simulation, the netlist is loaded. What kind of simulation do we now want to have?
Why do we use DC 0 and Pulse in Ngspice?
The ‘dc 0’ sets the operating point (which does not matter because of our simple circuit), ‘PULSE’ does matter only during transient simulation, so we keep it for simplicity. The 1 in ‘ac 1’ just helps us getting the ratio out/in, by dividing the output by 1, or just take it as is.
Where to find ngspice.exe in spice64?
Thus you will get C:\\Spice64 with several sub-directories. The main program ngspice.exe resides in folder C:\\Spice64\\bin. If you want to make use of PSPICE device models (often provided by the semicondctor companies), put a text file named .spiceinit into your user directory (C:\sers\\’your name’, found also in environmental variable USERPROFILE).
How to read the transistor parameters in Ngspice?
Transistor parameters such as small-signal parameters (taken at the calculated DC operating point) and model parameters can be read using the following commands: A complete list of accessible BSIM4 parameters are listed on page 608 of the ngspice user manual. Calculations can also be done on the parameters:
Where to save Ngspice files for beginners?
Line 1 is a title line. .end in line 5 denotes the end of the netlist. Put these lines into a text file named vdiv.cir and save it to the folder C:\\Spice64\\bin (If you are with MS Windows). Now start ngspice by double click onto ngspice.exe in C:\\Spice64\\bin.