ATMEGA644PA-AU Atmel, ATMEGA644PA-AU Datasheet - Page 252

• Manufacturer Part Number: ATMEGA644PA-AU
• Description: IC MCU 8BIT 64KB FLASH 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644PA-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, TWI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

22.7.4
8272A–AVR–01/10
ADC Accuracy Definitions
An n-bit single-ended ADC converts a voltage linearly between GND and V
(LSBs). The lowest code is read as 0, and the highest code is read as 2
Several parameters describe the deviation from the ideal behavior:
• Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition (at
Figure 22-10. Offset Error
• Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the last
Figure 22-11. Gain Error
• Integral Non-linearity (INL): After adjusting for offset and gain error, the INL is the maximum
164A/164PA/324A/324PA/644A/644PA/1284/1284P
0.5 LSB). Ideal value: 0 LSB.
transition (0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum).
Ideal value: 0 LSB
deviation of an actual transition compared to an ideal transition for any code. Ideal value: 0
LSB.
Output Code
Output Code
Offset
Error
Gain
Error
V
V
REF
REF
Input Voltage
Input Voltage
n
Ideal ADC
Actual ADC
Ideal ADC
Actual ADC
-1.
REF
in 2
n
steps
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