VBUS supplies the input voltage to the system regulator (SYSREG). VBUS voltage is supplied by an AC wall adapter or a USB port.
SYSREG supplies VSYS.
Features of SYSREG are the following:
- Operating voltage up to 5.5 V
- Overvoltage protection to 22 V
- Undervoltage detection
- USB port detection and a current limiter to comply with the USB specification
- Provides VBUSOUT voltage for host devices