8-bit AVR Microcontroller

Accuracy of Calibrated Internal 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. .

Table 1. Calibration Accuracy of Internal RC Oscillator
Calibration
 Method Target Frequency VCC Temperature Accuracy at given Voltage & Temperature
Factory
 Calibration 8.0MHz 2.7 - 4.0V 0°C - 85°C ±2%
User
 Calibration Fixed frequency within:
 7.3 - 8.1MHz Fixed voltage within:
 1.7 - 5.5V Fixed temp. within:
 -40°C - 85°C ±1%(1)
Note:
  1. 1.Accuracy of oscillator frequency at calibration point (fixed temperature and fixed voltage).
Parent topic: Clock Characteristics