i.MX6UL un-powered pin stress

[kanoumamoru]

Question about i.MX6UL concern with electric stress.

External I2C bus is always on. This bus is connected to i.MX6UL I2C pins (multiplex pin).

I2C voltage is keeping when i.MX6UL is completely power off status (all power off of i.MX6UL).

In this situation, Are there any electrical damage for i.MX6UL?

My customer feel nervous that i.MX6UL will lead to breakdown in this case.

If answer is yes, we should separate i.MX6's I2C bus when i.MX6UL is going to power off.

Best Regards,

kanou

[igorpadykov · Accepted solution]

Hi Kanou

you are right, external voltages should not be applied to processor

untill it fully powered up. This is described in sect.4.2.1 Power-up sequence

i.MX6UL Datasheet

NOTE
Need to ensure that there is no back voltage (leakage) from any supply on
the board towards the 3.3 V supply (for example, from the external
components that use both the 1.8 V and 3.3 V supplies).

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6ULCEC.pdf

Best regards
igor
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