Clarifications regarding SBCFS26 RSTB Short to battery fault

[Sivahari]

Hi NXP,

I am using MFS2613AMDA6 SBC IC and I have some doubts in RSTB short to battery fault.

Let us consider Case 1: RSTB is shorted to battery (+12V) or (3.3V/5V) before RSTB release state in SBC State machine.

1. Whether SBC can detect RSTB Short to battery during ABIST1 test?

Let us consider Case 2: RSTB is shorted to battery (+12V) or (3.3V/5V) after RSTB release state in SBC State machine (example: Sbc in normal state).

2.Whether SBC can detect RSTB Short to battery in normal state?

3. IF it detects in normal state, whether can we expect any indication signal like (INTB Low pulse)?

Thanks for your support.

[RafaR]

Hello Sivahari

Good Day!

1.- I could say no, the ABIST covers the short-to-high on RSTB, but it's not immediate since it monitors multiple voltage levels. Therefore, it's safe to say that it performs the monitoring after the 300µs it takes the ABIST to complete the monitoring.

Therefore, the RSTB release once the ABIST is done

2.- Yes

3.- RSTB_EVENT bit reports an activation of RSTB pin

I recommend that you review the safety manual and the full version of the datasheet found in the secure files of our FS26 page for more detailed information.

I hope this information has helped you, please let me know if you need help with anything else.

Have a great day and best of luck.

[Sivahari]

Hi RafaR,

Ok, Understood.

Please correct me if my understanding is wrong.

1.- I could say no, the ABIST covers the short-to-high on RSTB, but it's not immediate since it monitors multiple voltage levels. Therefore, it's safe to say that it performs the monitoring after the 300µs it takes the ABIST to complete the monitoring.

Therefore, the RSTB release once the ABIST is done.

My understanding:

SBCFS26 can covers RSTB Short to Battery detection while performing ABIST but only report after ABIST(300us) is completed.

SBCFS26 only report Short to battery fault when RSTB Pin short to +12V instead of +5v since SBC RSTB Pin will be high(5v) at normal state.

Thanks for your support.