Rainbow Electronics ATmega3290P_V - Manual (Page 315)

315
ATmega329/3290/649/6490
2552H–AVR–11/06
External Clock Drive
Waveforms Figure 137. External Clock Drive Waveforms
External Clock Drive
Maximum Speed vs. V
CC
Figure 138. Maximum Frequency vs. V
CC
(4 - 8 MHz).
V
IL1
V
IH1
Table 139. External Clock Drive
Symbol Parameter
V
CC
=1.8-5.5V V
CC
=2.7-5.5V V
CC
=4.5-5.5V
Units Min. Max. Min. Max. Min. Max.
1/t
CLCL
Oscillator
Frequency
0 4 0 8 0 16 MHz
t
CLCL
Clock Period 1000 125 62.5 ns
t
CHCX
High Time 400 50 25 ns
t
CLCX
Low Time 400 50 25 ns
t
CLCH
Rise Time 2.0 1.6 0.5
μs
t
CHCL
Fall Time 2.0 1.6 0.5
μs
Δ
t
CLCL
Change in period
from one clock
cycle to the next
2 2 2 %
8 MHz
4 MHz
1.8V 2.7V 5.5V
Safe Operating Area