S32K14xW MCU core power supply protection

[sfjia]

Hello,

As S32K has provide a LVD/LVR moudle to protect MCU power(VDD) from low votlage and also required a external IC for overvoltage or power spikes of VDD.

Is there any protection for MCU core power supply(VCORE,1.2V)?  Overvoltage or undervoltage protection? I didn't find it in Datasheet or Safety Manual.

Sifeng Jia

Best wish！

[aarul]

Hi

Yes, there is a LVR on internal power supply. Since it is on internal power supply it's electrical properties are not specified in datasheet. Functionally, the behavior can be seen in Reference Manual (See: Low Voltage Reset Flags Register (LVRFLG)).

Regards

-Aarul

[sfjia]

Hi Aarul

Thanks, I've got LVR for Vcore in the Reference Manual.

So, how about the overvoltage protection? Have you consisderd it in FMEDA?

BR.

Sifeng

[aarul]

There are no internal hardware mechanisms to monitor over-voltage condition. External watchdog monitor offers some coverage against this failure mode.

Regards

-Aarul

[sfjia]

Ok  got it.

So what if overvotlage happens to the core power supply?

Can moudles powerd by Vcore endure 3.3V for a while?  

And if not, how much voltage can these modules withstand?

Thank you,

BR!

[aarul]

Hi

Currently, we do not have specifications for tolerance levels if internal regulator goes out of range. For such a condition we expect the device to no longer operate reliably and assume that external WDOG can detect such conditions as Processor will no longer be functional.

Regards

-Aarul

[sfjia]

Hi Aarul

Considering that  external watchdog cannot provide enough diagnostic coverage. We are useing the ADC to read the internal supply, which is 1.219V,  to mornitor it is the in specific range. What threshold is reasonable ? Is 1.1V - 1.3V good？

Thanks and BR!

[aarul]

Hi

1.08 to 1.32 is the operating range for core VDD supply for normal mode.

Regards

-Aarul