Sage: Open Source Mathematics Software System

Sage is a free open-source mathematics software system licensed under the GPL. It builds on top of many existing open-source packages: NumPySciPymatplotlibSympyMaximaGAPFLINTR and many more
Access their combined power through a common, Python-based language or directly via interfaces or wrappers. → TourTutorialDocumentation
Mission: Creating a viable free open source alternative to Magma, Maple, Mathematica and Matlab.

 

Research Links

LTSPICE NetList

I want LTSPICE or otherwise to put out a spice deck like netlist as shown in the photo inset and the video embedded below. 

 I have not yet found a way to get this type of output.  All the output formats you can select for export in LTSPICE have the form:

Node#1

RefDes1.Pin1, RefDes2.Pin1 …….

Node#2

RefDes1.Pin2

Which of course is suited to pcb layout programs but not what I am trying to do.   See ExpressPCB Netlist format.

Research Links

LTSPICE Behavioral Modeling

Research Links

Nap0's  Control Library

To use this the library (text file) control.lib must be placed in the directory:


.\LTC\SwCADIII\lib\sub


The symbol files contained in control.zip must be placed in the directory:


.\LTC\SwCADIII\lib\sym\control 


(best in the new to be added directory control, so these new blocks do not mix up with the regular components).


Then the symbols are available to be selected amongst the regular components

Setting LTspice up for use with Electric

Research Links

LTspice is provided courtesy of Linear Technology, Inc. and authored by Mike Engelhardt. Possible contact for topo.

Extraction of MOSFET Parameters Lab using 4007 Array

Lab Document: Extraction of MOSFET Parameters using 4007 Array

My PDF Solution – Warning Will Robinson:  I never get 100% correct!

The following two measurements are where the MOSFET is in saturation and use the 8if method to nd ISpecific. In this
case because we are looking into the MOSFET source circuit we do not have to worry about slope factor n: Simply go to the
point where gms/ID=20 and read o the current the divide by 8 to arrive at the specic current.

Part_01_Vg_2_Vd_5  Part_1_Source_Drive

Vgate = 2:0 VD = 5 : Ispecific = 0:735 uAmp

Part_01_Vg_1p7_Vds_5V  Part_1_Source_Drive

Vgate = 1:7 Nominal Vt VD = 5 : ISpecific = 0:92 uAmp

The triode region determination of specic current is a little more complicated. I used Vds=15mVolts which results in if = 3
and ir = 2 which is convenient in the last part of the calculation of specic current.

Part_01_Vg_2_Vds_p015  Part_1_Source_Drive

Part_01_Vg_1p7_Vds_p015  Part_1_Source_Drive

Unabiguous-Extraction-Vt_If  UnAmbiguous-Parameter-Circuit

Vt_vs_Vs  n_vs_Vs       

A 180 Nanometer MOSFET Model – Using TSMC Transistor Models from MOSIS in LT Spice

If I use LTspice do I have to modify the SPICE models that I download from MOSIS? 

The models I download from CMOSedu.com work great with LTspice but I want to try some other technologies.

Yes, but you will have to change the

  • Change Level = 49 to Level = 8 for the BSIM3 models you download from MOSIS at: http://www.mosis.com/requests/test-data. 
  • For the BSIM4 models LTspice uses Level = 54 which is what MOSIS supplies so no change is needed.  

​In any case I would download the models, draft a ring oscillator, and compare the simulated oscillation frequency to the measured value reported by MOSIS in these files to verify that the models are working correctly.

 

Archive: The LTSPICE library file made up from MOSIS files and LTSPICE test analysis .asc file: 180nM-NMOS-PMOS-T92Y-MOSIS-LTSPICE-Files-V2.7z   

The archive file should work straight out of the box after extraction. Make a directory and extract to it.  It has the library file, symbols and an LTSPICE test circuit.

NOTE: When I vary the threshold voltage of the models with this version I do not see any changes in FET analysis.  I suspect something is not quite right with this setup.  No errors are flagged and everything runs.

 

Archive: This LTSPICE archive has model files that are used by using an nmos4 and pmos4 symbol.  Thus there is no subcircuit statements used in the library file.

NOTE: With this version  when I vary the threshold voltages I see the expected resultant change in the analysis output.

180nm analysis and model files 

The archive file should work straight out of the box after extraction. Make a directory and extract to it.  It has the library file, symbols and an LTSPICE test circuit.

Notes from the process follow. If you want to recreate the process for other MOSIS files they will be helpful.

Research Links

Model Files – No modifications. As is from MOSIS

Notes

  • To bring up the components attributes editor  for a part hold control button down and right click on the part.  Set the Prefix = X to set the components attributes editor to come up each time you right click on the part.

Auxiliary Links