Datasheet

335
8272A–AVR–01/10
164A/164PA/324A/324PA/644A/644PA/1284/1284P
27.4 System and Reset Characteristics
Notes: 1. The Power-on Reset will not work unless the supply voltage has been below V
POT
(falling).
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 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 = 101 and BODLEVEL = 110.
27.5 External Interrupts Characteristics
Table 27-12. Reset, Brown-out and Internal Voltage Reference Characteristics
Symbol Parameter Condition 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)
(1)
0.6 1.3 1.6 V
V
RST
RESET Pin Threshold Voltage 0.2V
CC
0.9V
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
= 2.7V, T
A
= 25°C1.0 1.1 1.2 V
t
BG
Bandgap reference start-up time V
CC
= 2.7V, T
A
= 25°C4070µs
I
BG
Bandgap reference current consumption V
CC
= 2.7V, T
A
= 25°C10 µA
Table 27-13. 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
Table 27-14. Asynchronous External Interrupt Characteristics
Symbol Parameter Condition Min Typ Max Units
t
INT
Minimum pulse width for asynchronous external interrupt 50 ns