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.
We know that the power sequence of PF 3000-A4 does not meet the power sequence of i.MX 6 UL.
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?