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Simulating a Bandgap in Cadence

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aryajur

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cadence netlisting procedure obsolete

Hello,
I am trying to simulate a bandgap circuit in Cadence. The problem is I only have the 0.18 um CMOS technology file. I wanted to know is how do I simulate a BJT in Spectre? Is there any place I can get the model file for that? or is there any way around it?
 

spectre bandgap ncsu

What you mean technology file? If that is Cadence technology file it is useless for simulation. First of all you should get model file for MOS and BJT transistor, resistor (temperature coefficient).
 

cpispectre.scs

In the process design kit (PDK) there should be a model for a vertical BJT transistor (look at paper in the PDK called Spice simulation model or smth like it)
 

bandgap circuit cadence

you can find it in the berkelay's web.
 

cadence ncsu bandgap

I meant that I have a NMOS PMOS 0.18um model file to use with Spectre. I don't have the model file for a vertical transistor. In which Process Design kit should I look for the model?
 

spectre vertical pnp models

I think you must find pnp model for spectre from foundry.
 

You can find design kit that have BJT
in NCSU web site. But if the PDK that you use
dont have a BJT in it. It dont make sense
to include extra model, since your not going to be able to fabricate it.
 

aryajur said:
Hello,
I am trying to simulate a bandgap circuit in Cadence. The problem is I only have the 0.18 um CMOS technology file. I wanted to know is how do I simulate a BJT in Spectre? Is there any place I can get the model file for that? or is there any way around it?

Here is a Spectre model file including BJT models:

**broken link removed**
 

Hello,
Thanks a lot for the model file but I am still having problems with it. I used a BJT symbol and then imported the cpiSpectre.scs library and added it.
When I try to simulate it I get the following error message:
" Netlist Warning: The netlisting procedure specified for (tsmc25Lib pnp spectre is obsolete "
And then it suggests to converti it using the Conversion toolbox from the CIW tools menu, but I cannot figure out what type of conversion to apply there.
Please suggest how do I proceed to do that. Thanks.
 

I just want it .I can simulate my project now.
 

GusTheCat said:
aryajur said:
Hello,
I am trying to simulate a bandgap circuit in Cadence. The problem is I only have the 0.18 um CMOS technology file. I wanted to know is how do I simulate a BJT in Spectre? Is there any place I can get the model file for that? or is there any way around it?

Here is a Spectre model file including BJT models:

h**p://www.ece.pdx.edu/~haiqiaox/instruction/ECE521Fall2004/cpiSpectre.scs

do you have model document for mentecarlo analysis?
thank you
 

we should use more high voltage BJT models.
 

Actually I need the SPectre model just to simulate the circuit for my course project. We won't be doing Layout in this project. About the file link already sent above, its not accepting that, it is asking to convert it to the new library, I don't get how to do that. I have also downloaded the NCSU CDK but I have to install it. How to go about that and where can I find the models I am looking for in that?
 

I do not think you need to convert anything. That is a warning which is not stopping the simulation. Your simulation will run just right.
Just note that the pnp is from 0.25 process what should not matter anyway.
 

You can find the model file named "mm018.scs" in Cadence directory. It includes all spectre models you want. For example,

1.8V P+/NW/PSUB 10x10, 5x5 and 2x2 vertical PNP bipolar and N+/PW/DNW 10x10, 5x5 and 2x2 vertical NPN bipolar

or

3.3V P+/NW/PSUB 10x10, 5x5 and 2x2 vertical PNP bipolar

I don't think you have to find such file elsewhere.
 

BTW, there are a pnp cell in the Library "cmosp18", and pnp and npn cells in the Library "analogLib".

You can use and simulate these BJTs directly.
 

There are cells in the library but they do not have any model files associated with them?? So I cannot do simulations once I have built up my schematic.
I tried simulationg with the file CpiSpectre.scs and the BJT works. But the problem is when I make the diode from that I get excessive current and from that I believe that its not the 0.18um or even the 0.5 um CMOS process vertical BJT parameters. Can anybody please suggest me from where I can get the parameters, for the BJT for the 0.18um process.
 

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