Datasheet

227
ATmega8A [DATASHEET]
8159E–AVR–02/2013
26.3 Speed Grades
Figure 26-1. Maximum Frequency vs. Vcc
26.4 Clock Characteristics
26.4.1 External Clock Drive Waveforms
Figure 26-2. External Clock Drive Waveforms
26.4.2 External Clock Drive
2.7V 4.5V 5.5V
Safe Operating Area
16 MHz
8 MHz
V
IL1
V
IH1
Table 26-1. External Clock Drive
Symbol Parameter
V
CC
= 2.7V to 5.5VV
CC
= 4.5V to 5.5V
UnitsMin Max Min Max
1/t
CLCL
Oscillator Frequency 0 8 0 16 MHz
t
CLCL
Clock Period 125 62.5 ns
t
CHCX
High Time 50 25 ns
t
CLCX
Low Time 50 25 ns
t
CLCH
Rise Time 1.6 0.5 s
t
CHCL
Fall Time 1.6 0.5 s
t
CLCL
Change in period from one
clock cycle to the next
22%