Rainbow Electronics ATtiny28L - Manual (Page 54)

54
ATtiny28L/V
1062E–10/01
External Clock Drive Waveforms
Figure 40. External Clock
:
Note: R should be in the range 3 - 100 k Ω, and C should be at least 20 pF.
VIL1
VIH1
External Clock Drive
Symbol Parameter
V
CC
= 1.8V to 2.7V V
CC
= 2.7V to 4.0V V
CC
= 4.0V to 5.5V
Units Min Max Min Max Min Max
1/t
CLCL
Oscillator Frequency 0.0 1.2 0.0 4.0 0.0 4.0 MHz
t
CLCL
Clock Period 833.0 250.0 250.0 ns
t
CHCX
High Time 333.0 100.0 100.0 ns
t
CLCX
Low Time 333.0 100.0 100.0 ns
t
CLCH
Rise Time 1.6 1.6 0.5 µs
t
CHCL
Fall Time 1.6 1.6 0.5 µs
Table 25. External RC Oscillator, Typical Frequencies
R [k Ω] C [pF] f
100.0 70.0 100.0 kHz
31.5 20.0 1.0 MHz
6.5 20.0 4.0 MHz