Datasheet

384
ATmega640/1280/1281/2560/2561
2549K–AVR–01/07
Note: 1. Values are guidelines only.
Calibrated Internal RC Oscillator Accuracy
Notes: 1. Voltage range for ATmega640V/1281V/1280V/2561V/2560V.
2. Voltage range for ATmega640/1281/1280/2561/2560.
AVCC Analog Supply Voltage V
CC
- 0.3 V
CC
+ 0.3 V
V
REF
Reference Voltage 2.7(2.0) AVCC - 0.5 V
V
IN
Input Voltage GNDV
CC
V
V
DIFF
Input Differential Voltage -V
REF
/Gain V
REF
/Gain V
ADC Conversion Output -511 511 LSB
Input Bandwidth 4kHz
V
INT
Internal Voltage Reference 2.3 2.56 2.8 V
R
REF
Reference Input Resistance 32 kΩ
R
AIN
Analog Input Resistance 100 MΩ
Table 171. ADC Characteristics, Differential Channels (Continued)
Symbol Parameter Condition Min
(1)
Typ
(1)
Max
(1)
Units
Table 172. Calibration Accuracy of Internal RC Oscillator
Frequency V
CC
Temperature Calibration Accuracy
Factory Calibration 8.0 MHz 3V 25°C±10%
User Calibration
7.3 - 8.1 MHz
1.8V - 5.5V
(1)
2.7V - 5.5V
(2)
-40°C - 85°C±1%