Hi, community.
Our customer made the i.MX6UL custom board with PF3000-A4 + DDR3 (not DDR3L).
Although they made total 10 sets, one i.MX6UL board is broken with over-current issue.
After some investigation, they found that DDR3 is short-circuited so huge current flows to i.MX6UL DDR3 IO Pads.
Below picture is thermal photo.
Question:
We know that the power sequence of PF 3000-A4 does not meet the power sequence of i.MX 6 UL.
That is,
In the specification of iMX 6 UL power-up sequence must be VDD_HIGH_IN -> VDD_SOC_IN,
but In PF 3000-A4, power is turned on in the order of SW1B(VDD_SOC_IN) -> V 33(VDD_HIGH_IN).
Is there a possibility that the interface of DDR 3 will be destroyed in this case?
If this answer is yes, why DDR I/F is broken?
Best Regards,
kanou
Solved! Go to Solution.
Hi Kanou,
Using the default power-up sequence of the PF3000A4 should not cause this over-current/short issue by using it with the i.Mx6UL + DDR3, I don’t think that this is the source of the problem.
If I properly understand, the current/short issue can only be seen in 1 of the 10 tested boards, correct?
And all 10 board are using the same components and same configuration, correct?
If the answer for both question above is “Yes”, then I strongly believe that the problem you are seen is related to a manufacture issue or even a low possibility caused due to a bad layout design.
You mentioned that you found a short-circuit on the DDR3, is it possible that this short is caused during manufacture or soldering process?
Have a great day,
Jose
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Hi Jose,
Thank you for your advices.
> If I properly understand, the current/short issue can only be seen in 1 of the 10 tested boards, correct?
Yes, you're correct.
I recognized we should be check the soldering processor or DDR.
Best Regards,
kanou
Hi Kanou,
Using the default power-up sequence of the PF3000A4 should not cause this over-current/short issue by using it with the i.Mx6UL + DDR3, I don’t think that this is the source of the problem.
If I properly understand, the current/short issue can only be seen in 1 of the 10 tested boards, correct?
And all 10 board are using the same components and same configuration, correct?
If the answer for both question above is “Yes”, then I strongly believe that the problem you are seen is related to a manufacture issue or even a low possibility caused due to a bad layout design.
You mentioned that you found a short-circuit on the DDR3, is it possible that this short is caused during manufacture or soldering process?
Have a great day,
Jose
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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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