Topic: What is STN1120

[BruceBushby]

Hi Vitaliy

I have searched the forums and have read this topic:
https://www.scantool.net/forum/index.php?topic=4683.0

However I am still confused. When I read this pdf:
http://www.scantool.net/scantool/downloads/73/microobd_200-product_brief.pdf

The picture in the pdf has the main IC marked as STN1120....however I can't find any information on STN1120.

What is the different between STN1120 and STN1110?

I have searched "www.obdsol.com"  and can't find any reference to STN1120.

We are about to assemble a prototype which uses the microobd reference design.....only to find the reference design uses STN1120 and NOT STN1110.

Any help/clarification would be much appreciated.

Thanks
Bruce

[Chris Fincher]

Hi Bruce,

The STN1120 is a variant of the STN1110.  As the post you linked had stated, there are various minor differences but the firmware is basically the same.  To add to that, the pin-out on both chips are the same for the QFN-28 package.

Regards,
Chris

[BruceBushby]

Hi Chris

Thanks for the update.

Going back to this thread:
https://www.scantool.net/forum/index.php?topic=4683.0

Where is says:
"...ICs run basically the same firmware, with minor differences that account for the different hardware..."

Given that people are using the microobd reference design ...to design their hardware....should these details/differences be documented?

Seems we now have two threads that have been answered with "there are slight differences" .... but nobody knows what these differences are?

Should I rather implement STN1120 in my project....I don't know....I have no idea how the firmware differs ...nor how it accounts for the different hardware.

Please forgive me if I have simply failed to locate the correct documents and hence my confusion.

Thanks again!
Bruce

[Chris Fincher]

The differences are mostly transparent, which would be why it's been answered with "slight differences".  Those differences usually present themselves in the default parameters which can be changed with ST commands if needed.  Although incomplete, the commands are documented in the STN11xx FRPM.

We do have a reference design for the STN1110 that can be found in the STN1110 Datasheet.  Even though the pin-out shown on the reference design looks different from the chip you probably have in mind, all pins are still present and documented in that datasheet as well.

Regards,
Chris