The major advantage of the BOR is that it consumes very little power (some uA). This feature improves the chip's power consumption during suspend. Note that LVR is turned off, and BOR is ON when the part enters suspend. This low power consumption helps the device stay within the suspend current limit set by the USB IF (in suspend, a low-power device can draw max. 500uA from the bus, and a high-power device with remote wake-up enabled can draw maximum 2.5mA).