320
8025I–AVR–02/09
ATmega48P/88P/168P/328P
26.5
System and Reset Characteristics
Notes:
1. Values are guidelines only.
2. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling).
Notes:
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 guarantees 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 = 110 and BODLEVEL = 101 for ATmega48P/88P/168PV and ATmega328P, and BODLEVEL = 101 and
BODLEVEL = 100 for ATmega48P/88P/168P/328P.
Table 26-3.
Reset, Brown-out and Internal Voltage Characteristics
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)
0.6
1.3
1.6
V
SR
ON
Power-on Slope Rate
0.01
10
V/ms
V
RST
RESET Pin Threshold Voltage
0.2 V
CC
0.9 V
CC
V
t
RST
Minimum pulse width on RESET Pin
2.5
µs
V
HYST
Brown-out Detector Hysteresis
50
mV
t
BOD
Min Pulse Width on Brown-out Reset
2
µs
V
BG
Bandgap reference voltage
V
CC
=2.7
T
A
=25°C
1.0
1.1
1.2
V
t
BG
Bandgap reference start-up time
V
CC
=2.7
T
A
=25°C
40
70
µs
I
BG
Bandgap reference current consumption
V
CC
=2.7
T
A
=25°C
10
µA
Table 26-4.
BODLEVEL Fuse Coding
BODLEVEL 2:0 Fuses
Min V
BOT
Typ V
BOT
Max V
BOT
Units
111
BOD Disabled
110
1.7
1.8
2.0
V
101
2.5
2.7
2.9
100
4.1
4.3
4.5
011
Reserved
010
001
000