The region of operation of MOS transistor

I believe most transistor models have a region operating point parameter so the most likely explanation is that the model is a subckt model and there is information in the CDF (opParamExprList) to tell it how to access the operating point information within the subckt model for the PDK you're using. If that's the case, the available parameters are only those in the opParamExprList setting.

A few questions:

1. Which PDK are you using?
2. If you go to Tools->CDF->Edit in the CIW, and give the library name and cell name of the transistor you're using, then switch to the Simulation Information tab and change the simulator to spectre does it show anything in the opParamExprList field? If so, can you copy and paste it here?
3. From the spectre log file, can you share the Circuit inventory section which will list the types of primitive components in use and so know which models are being used?

Thanks,

Andrew

Hi Andrew,

Thank you for your reply.

Please see the attached picture.

Thanks.

Hi Andrew,

Thank you for your reply.

Please see the attached picture.

Thanks.

Are you sure that's the primitive transistor device in the PDK? It seems rather unlikely that the simulation information would be blank for that.

You also only answered one of my three questions (and even then I'm not convinced you really answered the question...). Diagnosing what's wrong in a vacuum is rather tricky!

Andrew

Dear Andrew,

I apologize for the late response,

1-Which PDK are you using?

I use XFAB technology.

2- If you go to Tools->CDF->Edit in the CIW, and give the library name and cell name of the transistor you're using, then switch to the Simulation Information tab and change the simulator to spectre does it show anything in the opParamExprList field? If so, can you copy and paste it here?

I did as you said and it is as in the previous picture.

3- From the spectre log file, can you share the Circuit inventory section which will list the types of primitive components in use and so know which models are being used?

I do not know how can I do that.

I am looking to hearing from you.

Regards.

OK, so 6 months later you reply and don't tell me the PDK you're using ("XFAB technology" doesn't tell me which XFAB technology you're using). You also have blanked out the library and cell so I have no means of checking what might be going on.

You really are going to have to provide more information if you expect an answer!

Andrew

Dear Andrew,

Thanks for the reply.

I am a beginner at using cadence (Virtuoso) and XFAB technology, therefore I answering as I understand what you mean.

I am using XFAB (XT018), I am not sure if this is what you want to know. I made it blank for license reasons, I don't know if this is allowed or not.

Regards,

I suggest if you can't share the device name that has the problem, you contact XFAB. It's pretty much impossible to give you assistance without more details (the process name is one thing, but only part of the information needed). 

Regards,

Andrew

Thanks for the reply,

what do you mean by process name?

I am working on XFAB technology, The Lib name is (Primlib) and the technology is 180nm (XT018 mean the technology is 180nm).

 is this what you need to know? if not please tell me.

Regards.

You've told me the process name (XT018); you have now told me the library name, but you've not told me the device name that you're trying to annotate the operating points for. It could be anything!

Andrew

Hi Andrew

The device is a transistor (MOSFET) as in the title of this post (The region of operation of MOS transistor).

PhD Student said:

The device is a transistor (MOSFET) as in the title of this post (The region of operation of MOS transistor).

This is getting rather frustrating, since you keep failing to answer simple questions and only give vague information. I spent a bit more time on it, but I've reached my limit - for anything further, please contact X-FAB since this is their kit, not Cadence's.

Anyway, what I did:

1. There are 19 MOSFETs in the PRIMLIB for the PDK version I have (I picked one metal stack arbitrarily but I don't think that would affect it). More if you include MOSCAPs. So "the device is a transistor" is not terribly helpful.
2. The Spectre simulation information is not blank for any of them - so I have no idea why it would be blank for (say) PRIMLIB/nd5 or PRIMLIB/ne5 (for example). Perhaps your setup is wrong or you were looking at the wrong thing.
3. I see that opParamExprList is used for all 19 MOS devices, and for a couple I checked (at least) it did not include any mapping for "region". The mapping retrieves the information from a device within a subckt model (.m1 or .m2 from the few I looked at), but they've not included region.
4. I could explain to you how to modify the CDF to update it to add additional operating point parameters, but I have little confidence that you'd be able to do this correctly from instructions on a forum unless they were extremely prescriptive. The fact that your CDF form is blank suggests that something is not right. Also, you'd need write access to the PDK, and most people do not want to alter the PDK setup for fear of breaking it.

So this reinforces my view that you should contact X-FAB - maybe they can update the PDK or maybe they can provide you support on getting what you want from their technology.

Good luck,

Andrew

Dear Andrew,

Thank you for the reply.

Regards.