Datasheet

45
8024A–AVR–04/08
ATmega8HVA/16HVA
The BOD is automatically enabled in all modes of operation, except in Power-off mode.
When the BOD is enabled, and V
REG
decreases to a value below the trigger level (V
BOT-
in Fig-
ure 11-5), the Brown-out Reset is immediately activated. When V
REG
increases above the trigger
level (V
BOT+
in Figure 11-5), the delay counter starts the MCU after the Time-out period t
TOUT
has
expired.
Figure 11-5. Brown-out Reset During Operation
11.2.5 Black-out Detection
As an extra security feature, the chip will automatically enter Power-off if V
REG
drops below
V
BLOT
. V
BLOT
will always be well below the BOD level, V
BOT
.
V
CC
RESET
T
IME-OUT
I
NTERNAL
RESET
V
BOT-
V
BOT+
t
TOUT