Part Number:AM3352
Hello,
Does the USB controller generate a VBUS error interrupt when the USBx_VBUS detects 5.25 V or more?
I understand that 5.25 V for USBx_VBUS is absolute maximum rating and recommended operating condition. According to TRM, VBUS error seems to occur when the USBx_VBUS input is less than 4.4 V, but the upper limit is not mentioned.
On our target board, there is ripple at 5 V VBUS power supply. When the logs of VBUS error interrupt are output several times during Linux start-up and failing to start Kernel, it looks like VBUS voltage reaches around 5.25 V at the time. During this time, the USB device is not connected and USBx_DRVVBUS goes low.
The modified hardware to improve ripple, the phenomena can be suppressed. However, I'd like to understand the specifications of the USB controller and clarify the cause of this phenomenon.
Regards,
Kazu