SPRADO3B December 2024 – September 2025 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
The VBUS power supply is sourced from an external host. USB standard recommends connecting < 10μF capacitor to the VBUS close to the USB Type-B connector.
The recommendation is to follow the USB VBUS Design Guidelines section of the processor-specific data sheet to divide the USB VBUS voltage (supply near the USB interface connector using resistor divider and zener diode protection) before connecting to USBn_VBUS input.
The zener diode protection (recommended) can be considered to be optional if custom board designer is absolutely sure that the board never sees a VBUS voltage > 5.5V (sourced on-board).
Connecting an on-board supply that is not switched (permanent) or connecting a permanent 3.3V supply with equivalent divider or connecting a permanent 1.65V directly to USBn_VBUS is not recommended or allowed. A switched supply that can be disconnected at the end of the session and switched back during the start of the next session is recommended.