Datasheet

177
8006H–AVR–10/09
ATtiny24/44/84
20.4.2 External Clock Drive
Figure 20-3. External Clock Drive Waveform
20.5 System and Reset Characteristics
Note: 1. Values are guidelines, only
V
IL1
V
IH1
Table 20-3. 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 20-4. Reset, Brown-out, and Internal Voltage Characteristics
Symbol Parameter Condition Min
(1)
Typ
(1)
Max
(1)
Units
V
RST
RESET Pin Threshold Voltage 0.2 V
CC
0.9V
CC
V
t
RST
Minimum pulse width on RESET
Pin
V
CC
= 1.8V
V
CC
= 3V
V
CC
= 5V
2000
700
400
ns
V
HYST
Brown-out Detector Hysteresis 50 mV
t
BOD
Min Pulse Width on
Brown-out Reset
2µs
V
BG
Internal bandgap reference
voltage
V
CC
= 5V
T
A
= 25°C
1.0 1.1 1.2 V
t
BG
Internal bandgap reference
start-up time
V
CC
= 5V
T
A
= 25°C
40 70 µs
I
BG
Internal bandgap reference
current consumption
V
CC
= 5V
T
A
= 25°C
15 µA