Datasheet

336
8021G–AVR–03/11
ATmega329P/3290P
28.5 System and Reset Characteristics
Note: 1. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling)
28.6 Standard Power-on Reset
This implementation of power-on reset existed in early 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 B and older
• ATmega3290P revision B and older
Note: 1. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling)
Table 28-6. Reset, Brown-out, and Internal Voltage Characteristics
Symbol Parameter Condition Min Typ Max Units
V
RST
RESET Pin Threshold Voltage V
CC
= 3V 0.2 V
CC
0.9 V
CC
V
t
RST
Minimum pulse width on RESET
Pin
V
CC
= 3V 2.5 µs
V
HYST
Brown-out Detector Hysteresis 50 mV
t
BOD
Min Pulse Width on Brown-out
Reset
2µs
V
BG
Bandgap reference voltage
V
CC
= 2.7V,
T
A
=25°C
1.0 1.1 1.2 V
t
BG
Bandgap reference start-up time
V
CC
= 2.7V,
T
A
=25°C
40 70 µs
I
BG
Bandgap reference current
consumption
V
CC
= 2.7V,
T
A
=25°C
15 µA
Table 28-7. Reset, Brown-out, and Internal Voltage Reference Characteristics,
T
A
= -40°C to 85°C
Symbol Parameter Min. Typ Max Units
V
POT
Power-on Reset Threshold Voltage (rising) 0.7 1.0 1.4 V
Power-on Reset Threshold Voltage (falling)
(1)
0.05 0.9 1.3 V
SR
ON
Power-on Slope Rate 0.01 4.5 V/ms