Datasheet

337
8021G–AVR–03/11
ATmega329P/3290P
28.7 Enhanced Power-on Reset
This implementation of power-on reset exists in newer versions of
ATmega329P/ATmega3290P. The table below describes the characteristics of this power-on
reset and it is valid for the following devices only:
• ATmega329P revision C and newer
• ATmega3290P revision C and newer
Notes: 1. Values are guidelines only.
2. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling)
28.8 Brown-out Detection
Note: 1. V
BOT
may be below nominal minimum operating voltage for some devices. For devices where
this is the case, the device is tested down to V
CC
= V
BOT
during the production test. This guar-
antees that a Brown-Out Reset will occur before V
CC
drops to a voltage where correct
operation of the microcontroller is no longer guaranteed. The test is performed using
BODLEVEL = 10 for ATmega329P/3290PV and BODLEVEL = 01 for ATmega329P/3290P.
Table 28-8. Reset, Brown-out and Internal Voltage Reference Characteristics
(1)
,
T
A
= -40°C to 85°C
Symbol Parameter Min. Typ Max Units
V
POT
Power-on Reset Threshold Voltage (rising) 1.1 1.4 1.6 V
Power-on Reset Threshold Voltage (falling)
(2)
0.6 1.3 1.6 V
SR
ON
Power-on Slope Rate 0.01 10 V/ms
Table 28-9. BODLEVEL Fuse Coding
(1)
BODLEVEL 1:0 Fuses Min. V
BOT
Typ V
BOT
Max V
BOT
Units
11 BOD Disabled
10 1.7 1.8 2
V01 2.5 2.7 2.9
00 4.1 4.3 4.5