AM3352: IBIS model capacitance matrix

Sh.Sasaki

Guru 13625 points

Part Number: AM3352

Hi all,

In the IBIS Package Model Capacitance Matrix,

the self value (eg, the H4 value on the matrix for the H4 pin) will be a positive value

and the other mutual capacitance values should be a negative value.

AM335x ZCZ IBIS Model (Rev. C)
www.ti.com/.../toolssoftware

Looking at this model, all mutual capacitances are positive values, so an error has occurred.

By setting these values to a negative value, the error is solved.

Why are mutual capacitance values all defined as positive values?

Best regards,

Sasaki

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The IBIS experts have been notified. They will respond here.

0 Sh.Sasaki over 8 years ago in reply to Biser Gatchev-XID

Guru 13625 points

My customer needs this information.
Is there any information?

0 Bill Taboada over 7 years ago in reply to Sh.Sasaki

TI__Mastermind 42545 points

Hi Biser,
I had to go back to the design team concerning this question. I will update when I get a response.
Regards, Bill

0 Sh.Sasaki over 7 years ago in reply to Bill Taboada

Guru 13625 points

Hi Biser-san, Bill-san,

I got additional information from my customer.

My customers are using the following tools.

ibischeck of HyperLynx GHz Ver.9.4.2 (Mentor)

Best regards,

Sasaki

0 Bill Taboada over 7 years ago in reply to Sh.Sasaki

TI__Mastermind 42545 points

Hi Sasaki-san,
Was this problem only flagged at the IBIS checker phase? Is the customer checking against the right version of IBIS? The IBIS file was checked against IBIS ver 4.2 for compatibility using IBISCHK5 V5.1.4 with no errors flagged.
Regards, Bill

0 Sh.Sasaki over 7 years ago in reply to Bill Taboada

Guru 13625 points

Hi Bill-san,

Thnak you for your support.

I will check with my customer.

BEst regards,

Sasaki

0 Sh.Sasaki over 7 years ago in reply to Sh.Sasaki

Guru 13625 points

Hi Bill-san,

My customer is using IBISCHK6 V6.1.2.

Is this version compatible?

And I'd like to know the web link of the tool(IBISCHK5 V5.1.4) you used.

And let me know the following.

sasaki said:

AM335x ZCZ IBIS Model (Rev. C)
www.ti.com/.../toolssoftware

Looking at this model, all mutual capacitances are positive values, so an error has occurred.

By setting these values to a negative value, the error is solved.

Is this positive value correct?

Best regards,

Sasaki

0 Bill Taboada over 7 years ago in reply to Sh.Sasaki

TI__Mastermind 42545 points

Hi Sasaki-san,
The IBIS checkers are available for download from the IBIS.org website. IBISCHK5 can be found here.
https://ibis.org/ibischk5/
I also downloaded the IBISCHK6 package and ran the checker using that software. With that version, I am seeing the error mentioned by the customer but it is not present when running the earlier version of the checker. I opened the Error Matrix spreadsheet for IBISCHK5 and that error message didn't exist.
I am still discussing this with the design team but the IBIS model is based on the IBIS spec version 4.2. It is likely that this is a requirement that was added in later versions of IBIS.
Regards, Bill

0 Sh.Sasaki over 7 years ago in reply to Bill Taboada

Guru 13625 points

Hi Bill-san,

Thank you for your support!

I understand the dependency on the version.

If you have any new information please let me know.

Best regards,

Sasaki

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AM3352: IBIS model capacitance matrix