The purpose of the Brown-Out Detector (BOD) is to actively monitor power supply voltage and to ensure that the MCU is not operating at a too low voltage. BOD is configured by BODLEVEL fuses. BOD can be configured separately for Active/Idle and sleep modes to track for indeterminate voltage levels. This allows for the BOD to be enabled only in Active and Idle mode. In AVR XMEGA devices, to reduce power it is recommended to disable BOD in Power-down sleep mode.
When BOD is disabled in software, it is turned OFF immediately after entering the sleep mode and automatically turned ON upon wake-up for monitoring supply voltage.
Disable BOD in sleep modes through application software to conserve power.