I designed a product using iMX287 as MCU.Most of the time the product work normal,sometimes the product does not work with boot fail . The probability is one in dozens. In this abnormal condition ,the device will continuously ‘died’ until turn off the 5V power and turn on it. I found the VDDIO drop down to 3.1V, VDDD drop down to 1.05V and VDDA drop down to 1.04V.I don't know why this happened, and I also don't know in which condition this will happen. How can I solve this problem? Is there some problem with my schematic? I use 5V only source .