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Model files
MOS models
These are sample models obtained from public domain data such as parametric run results published on MOSIS's website or predictive technology models from http://ptm.asu.edu/. These are provided so that students can get a feel for performance of circuits in various technologies. Do not use these to simulate circuits that are to be fabricated-get the models for your process from the fabrication foundry. Click on the process name for more information
For realistic modeling of circuits, include the drain and source junction capacitances by specifying appropriate values of "ad", "as", "pd", "ps" for all MOS transistors. In absence of layout information, you can use 2Lmin to be junction length(i.e. 0.36µm in a 0.18µm technology) and set ad = as = 2WLmin and pd = ps = 2(W+2Lmin).
- TSMC 0.35µm CMOS, Vdd=3.3V, Wmin=0.6µm, Lmin=0.4µm: Models for Spectre, Eldo and others
- TSMC 0.25µm CMOS, Vdd=2.5V, Wmin=0.36µm, Lmin=0.24µm: Models for Spectre, Eldo and others
- TSMC 0.18µm CMOS, Vdd=1.8V, Wmin=0.27µm, Lmin=0.18µm: Models for Spectre, Eldo and others
- IBM 0.18µm CMOS, Vdd=1.8V, Wmin=0.24µm, Lmin=0.18µm: Model file for Spectre, Eldo and others
- IBM 0.13µm CMOS, Vdd=1.2V, Wmin=0.16µm, Lmin=0.12µm: Model file for Spectre, Eldo and others
- 45nm high performance predictive technology model, Vdd=1V, Wmin=90nm, Lmin=45nm
- 32nm high performance predictive technology model, Vdd=0.9V, Wmin=64nm, Lmin=32nm
- 22nm high performance predictive technology model, Vdd=0.8V, Wmin=44nm, Lmin=22nm
- 16nm high performance predictive technology model, Vdd=0.7V, Wmin=32nm, Lmin=16nm
- Ideal diode, NPN, and PNP transistors: Models for Spectre, Eldo and others
- 2N2222(NPN) and 2N2907(PNP): Models for Spectre, Eldo and others
Add the following line to your netlist to use these models with Eldo
.option compat
Opamp models
Use these models only with +/-5V supply. Because of the way theyy are modeled, the gain, and more crucially, the unity gain frequency is very sensitive to the supply voltage. At +/-6V, the dc gain and unity gain frequency are more than 3x higher than at +/-5V.
- OPA656-230MHz gain bandwidth operational amplifier: Models for Spectre, Eldo and others.
- OPA657-1600MHz gain bandwidth operational amplifier: Models for Spectre, Eldo and others. (OPA657 is not unity gain stable)
System level simulators
- Matlab, Octave,
or Scilab can
be used for system simulations and numerical calculations.
- Maxima can be
used for symbolic calculations.
Drawing tools
Xcircuit is an excellent tool for drawing publication quality circuits. You can use it for your reports. It can also be used for schematic capture and netlisting, but is a bit cumbersome. Download the latest version of Xcircuit at here. You might want to go through the schematic capture tutorial in order get familiar with the netlisting process. If you use machines in FPGA/VLSI/IE labs, check to see if Xcircuit is already installed.
Circuit Simulators in our labs
Cadence is a front to back IC design environment and is installed in our research labs. If you are working on a project in these labs, you can also use the simulator for coursework. To use the MOS models above, use the MOS symbols from analogLib with the right model names(cmosp and cmosn for pMOS and nMOS respectively). ahdlLib has a lot of macromodels.
Freeware circuit simulators
Any simulator that is capable of using the models below can be used for your simulations. Free tools that have schematic capture and simulation capabilities include the following. You may have to make some trivial modifications to the syntax of model files for these simulators.
- QSpice from Qorvo, also from the creator of LT Spice.
- LTspice from Linear technology is suitable for most simulations required for class assignments. Includes schematic capture and waveform viewer tools. Runs on MS Windows. Thanks to T Siva Viswanathan, here is a howto on using the models below with LT Spice(cmosn.asy and cmosp.asy)
- NGSpice is the continuation of original Berkeley SPICE3. Freely downloadable full simulator. Includes periodic steady-state analysis for autonomous circuits.