ATTINY24_14 Datasheet, PDF (176/238 Pages) ATMEL Corporation – High Performance, Low Power AVR

Figure 20-2. Maximum Frequency vs. V_CC (ATtiny24/44/84)
20 MHz
10 MHz
Safe Operating Area
2.7V
4.5V
5.5V
20.4 Clock Characteristics
20.4.1
Accuracy of Calibrated Internal RC Oscillator
It is possible to manually calibrate the internal oscillator to be more accurate than default factory
calibration. Note that the oscillator frequency depends on temperature and voltage. Voltage and
temperature characteristics can be found in Figure 21-40 on page 206 and Figure 21-41 on
page 206.
Table 20-2. Calibration Accuracy of Internal RC Oscillator
Calibration
Method
Target Frequency
V_CC
Factory
Calibration
8.0 MHz
3V
User
Calibration
Fixed frequency within:
7.3 – 8.1 MHz
Fixed voltage within:
1.8 – 5.5V⁽²⁾
2.7 – 5.5V⁽³⁾
Temperature
25°C
Fixed temperature
within:
-40°C to +85°C
Accuracy at given voltage
& temperature⁽¹⁾
±10%
±1%
Notes:
1. Accuracy of oscillator frequency at calibration point (fixed temperature and fixed voltage).
2. Voltage range for ATtiny24V/44V/84V.
3. Voltage range for ATtiny24/44/84.
176 ATtiny24/44/84
8006K–AVR–10/10