Datasheet

180
7701F–AVR–10/12
Atmel ATtiny24/44/84 [Preliminary]
22.3 Clock Characterizations
22.3.1 Calibrated Internal RC Oscillator Accuracy
Note: 1. The overall jitter increase proportionally to the divider ratio
Example: with Oscillator divided by 32, jitter standard deviation will be 32 × 0.4ns = 12.8ns.
22.3.2 External Clock Drive Waveforms
Figure 22-2. External Clock Drive Waveforms
22.3.3 External Clock Drive
Table 22-2. Calibration Accuracy of Internal RC Oscillator
Frequency V
CC
Temperature Accuracy
Factory
Calibration
8.0MHz 3V 25°C ±2%
User Calibration 7.3 - 8.1MHz 2.7V - 5.5V -40°C - 125°C ±20%
Oscillator Jitter 8.0MHz 2.7V - 5.5V -40°C - 125° Standard Deviation 0.4ns
(1)
V
IL1
V
IH1
Table 22-3. External Clock Drive
Symbol Parameter
V
CC
= 2.7 - 5.5V V
CC
= 4.5 - 5.5V
UnitsMin. Max. Min. Max.
1/t
CLCL
Clock Frequency 0 10 0 20 MHz
t
CLCL
Clock Period 100 50 ns
t
CHCX
High Time 40 20 ns
t
CLCX
Low Time 40 20 ns
t
CLCH
Rise Time 1.6 0.5 µs
t
CHCL
Fall Time 1.6 0.5 µs
Δt
CLCL
Change in period from one clock cycle to the next 2 2 %