S12Z LIN overcurrent Interrupt

[charu]

Dear Team, please suggest How the LIN over current interrupt will be triggered ? How I can simulate the scenarios on test bench ? Ex: LP0IE_LPOCIE =1U; /* Enable the LIN Over Current interrupt * Thanks Charudatta

[danielmartynek]

Hello @charu,

You didn't specify the part.

The over-current protection is described in the RM.

S12ZVL, RM, re2.48, Section 21.4.4.1 Overcurrent Interrupt.

The condition can be detected in the dominant state (after tOCLIM) when the current through the A-meter exceeds the current limit, for example, because of a shorted to VBAT.

danielmartynek_0-1617699400605.png

danielmartynek_1-1617699609947.png

Regards,

Daniel

[charu]

Hello Daniel,

Thanks for quick response.

Shorting of LIN Pin and VBAT will triggered the LIN overcurrent interrupt

Let me correct if my understanding is wrong.

While shorting LIN pin and VBAT, what ohm and wattage register we should use ?

OR

Directly we can Short LIN pin and VBAT

Thanks & Regards,

Charudatta

[danielmartynek]

Hello Charudatta,

It can be shorted directly.

The driver itself limits the current, you can read in Table D-2, #2, footnote 4:

"At temperatures above 25C the current may be naturally limited by the driver, in this case the limitation circuit is not engaged and the flag is not set."

Regards,

Daniel

[charu]

Hello Daniel,

Can you please confirm at which current value LIN overcurrent Interrupt will be triggered ?

If LIN overcurrent interrupt is triggered, when current value is more than 200ma,but as seen in TRF s12ZVL Micro circuitry is limiting the current at 200ma, in that case as per our understanding we will never see the LIN overcurrent interrupt  get trigger.

we want to test the LIN Overcurrent Interrupt scenario without damaging the Micro.

Please suggest.

Thanks You in Advanced.

Best Regards,

Charudatta

[danielmartynek]

Hello Charudatta,

Please have a look at the LIN PHY specification.

This is from the S12ZVL RM, rev.2.48

danielmartynek_0-1617873401697.png

As you can see, the current is internally limited by the low side driver and it should not be possible to reach 200mA through the LIN pin.

The over-current interrupt asserts in the range of 40 - 200mA of I_LIN_LIM.

However, footnote 4 states the following:

danielmartynek_6-1617873598289.png

That means that at higher temperature, the current might be limited below the I_LIN_LIM assert level.

Regards,

Daniel