MCU damage due to pin8 and pin9 short circuit when applying S912ZVML12AMKHR

[yq1]

hello

When applying S912ZVML12AMKHR, using the pin9 BCTL of MCU plus PNP transistor to realize 12V to 5V, pin8 is configured as a high resistance input, I found that short-circuiting pin8 and pin9 leads to immediate damage to MCU, how to configure pin8 to avoid the problem of damage to MCU due to the short-circuiting of pin8 and pin9,

thanks!

[Rian]

How long will it take you to complete? "The current would need to be limited below 2.5mA (Table A-12, #17a).

AN4731 Understanding Injection Current on NXP Automotive Microcontrollers

https://www.nxp.com/docs/en/application-note/AN4731.pdf/ white screen "

[yq1]

Hi Rian
I short-circuited pin8 and pin9 with water droplets, not directly with metal, the water droplets should have a large resistance, theoretically it should not be damaged immediately, is it possible to affect the voltage stability of the BCTL through the short circuit of water droplets, resulting in raising the external 5V voltage, thank you!

[danielmartynek]

Hello @yq1,

Absolute Maximum Ratings (RM, Table A-2) are 42V for BCTL and 6V for Digital I/O inputs.

"Absolute maximum ratings are stress ratings only. A functional operation outside these ranges is not guaranteed. Stress beyond these limits may affect the reliability or cause permanent damage of the device." (A.1.4).

When V_BCTL > V_PS5 and short-circuit, the injection currect can damage the MCU.

The current would need to be limited below 2.5mA (Table A-12, #17a).

AN4731 Understanding Injection Current on NXP Automotive Microcontrollers

https://www.nxp.com/docs/en/application-note/AN4731.pdf

Regards,

Daniel

[yq1]

Hi Daniel
I short-circuited pin8 and pin9 with water droplets, not directly with metal, the water droplets should have a large resistance, theoretically it should not be damaged immediately, is it possible to affect the voltage stability of the BCTL through the short circuit of water droplets, resulting in raising the external 5V voltage, thank you!

[danielmartynek]

Hi @yq1,

That is possible if the short-circuit manages to drive the BCTL voltage lower.

Regards,

Daniel