Datasheet

188
8197C–AVR–05/11
ATtiny261A/461A/861A
19.4.2 External Clock Drive
Figure 19-2. External Clock Drive Waveforms
19.5 System and Reset Characteristics
Notes: 1. Not tested. Values are guidelines, only.
V
IL1
V
IH1
Table 19-3. External Clock Drive Characteristics
Symbol Parameter
V
CC
= 1.8 - 5.5V V
CC
= 2.7 - 5.5V V
CC
= 4.5 - 5.5V
UnitsMin. Max. Min. Max. Min. Max.
1/t
CLCL
Clock Frequency 0 4 0 10 0 20 MHz
t
CLCL
Clock Period 250 100 50 ns
t
CHCX
High Time 100 40 20 ns
t
CLCX
Low Time 100 40 20 ns
t
CLCH
Rise Time 2.0 1.6 0.5 µs
t
CHCL
Fall Time 2.0 1.6 0.5 µs
Δt
CLCL
Change in period from one clock cycle to the next 2 2 2 %
Table 19-4. Reset, Brown-out, and Internal Voltage Characteristics
Symbol Parameter Condition Min Typ Max Units
V
RST
RESET Pin Threshold Voltage
(1)
0.2 V
CC
0.9 V
CC
V
t
RST
Min pulse width on RESET Pin
(1)
V
CC
= 3V 2.5 µs
V
HYST
Brown-out Detector Hysteresis
(1)
50 mV
t
BOD
Min Pulse Width on
Brown-out Reset
(1)
2µs
V
BG
Internal bandgap voltage
V
CC
= 2.7V
T
A
=25°C
1.0 1.1 1.2 V
t
BG
Internal bandgap start-up time
(1)
V
CC
= 5V
T
A
=25°C
40 70 µs
I
BG
Internal bandgap reference
current consumption
(1)
V
CC
= 5V
T
A
=25°C
15 µA