Data Sheet

318
8161D–AVR–10/09
ATmega48PA/88PA/168PA/328P
28.5 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, 101 and 100.
Table 28-3. Reset, Brown-out and Internal Voltage Characteristics
(1)
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
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 28-4. BODLEVEL Fuse Coding
(1)
BODLEVEL 2:0 Fuses Min V
BOT
Typ V
BOT
Max V
BOT
Units
111 BOD Disabled
110 1.7 1.8 2.0
V101 2.5 2.7 2.9
100 4.1 4.3 4.5
011
Reserved
010
001
000