
161
8048C–AVR–02/12
ATtiny43U
20.5
System and Reset Characteristics
Note:
1. The Power-on Reset will not work unless the supply voltage has been below VPOT (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 VCC = VBOT during the production test. This guarantees that a Brown-out Reset will occur before VCC drops to
a voltage where correct operation of the microcontroller is no longer guaranteed.
20.6
External Interrupt Characteristics
Table 20-4.
Reset, Brown-Out and Internal Voltage Characteristics
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
POT
Power-on Reset Threshold Voltage (rising)
TA = -40 - 85°C1.1
1.4
1.6
V
Power-on Reset Threshold Voltage (fallin
g)(1)T
A = -40 - 85°C0.6
1.3
1.6
V
VPSR
Power-On Slope Rate
TA = -40 - 85°C0.01
V/ms
VRST
RESET Pin Threshold
0.2VCC
0.9VCC
V
tRST
Minimum pulse width on RESET Pin
V
CC = 1.8V
VCC = 3V
VCC = 5V
2000
700
400
ns
V
HYST
Brown-out Detector Hysteresis
50
mV
tBOD
Min Pulse Width on Brown-out Reset
2
s
VBG
Internal bandgap reference voltage
VCC = 2.7V
T
A = 25°C
1.0
1.1
1.2
V
t
BG
Internal bandgap reference start-up time
VCC = 2.7V
TA = 25°C
40
70
s
IBG
Internal bandgap reference current consumption
V
CC = 2.7V,
TA = 25°C
15
A
Table 20-5.
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
Table 20-6.
Characteristics of Asynchronous External Interrupt
Symbol
Parameter
Condition
Min
Typ
Max
Unit
t
INT
Minimum pulse width for asynchronous external
interrupt
50
ns