
209
8008H–AVR–04/11
ATtiny48/88
22.4.2
External Clock Drive
Figure 22-2. External Clock Drive Waveforms
Note:
All DC Characteristics contained in this datasheet are based on simulation and characterization of
other AVR microcontrollers manufactured in the same process technology.
22.5
System and Reset Characterizations
Table 22-2.
External Clock Drive
Symbol
Parameter
VCC = 1.8-5.5V
VCC = 2.7-5.5V
VCC = 4.5-5.5V
Units
Min.
Max.
Min.
Max.
Min.
Max.
1/tCLCL
Oscillator
Frequency
02
06
0
12
MHz
tCLCL
Clock Period
250
166
83
ns
tCHCX
High Time
120
80
40
ns
tCLCX
Low Time
120
80
40
ns
tCLCH
Rise Time
2.0
1.6
0.5
s
tCHCL
Fall Time
2.0
1.6
0.5
s
Δt
CLCL
Change in period
from one clock
cycle to the next
22
2
%
VIL1
VIH1
Table 22-3.
Reset, Brown-out, and Internal Voltage Characteristics
(1)Symbol
Parameter
Condition
Min
Typ
Max
Units
VPOT
Power-on Reset Threshold
Voltage (rising)
TA = -40 to +85°C1.5
V
Power-on Reset Threshold
TA = -40 to +85°C1.2
V
VRST
RESET Pin Threshold
Voltage
0.2VCC
0.9VCC
V
tRST
Minimum pulse width on
RESET Pin
VCC = 1.8V
VCC = 3V
VCC = 5V
2000
700
400
ns