ATMEGA644A-PU Atmel, ATMEGA644A-PU Datasheet - Page 253

• Manufacturer Part Number: ATMEGA644A-PU
• Description: IC MCU AVR 64K FLASH 40PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644A-PU

• 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: 40-DIP (0.600", 15.24mm)
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: JTAG, TWI, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8272A–AVR–01/10
Figure 22-12. Integral Non-linearity (INL)
• Differential Non-linearity (DNL): The maximum deviation of the actual code width (the interval
Figure 22-13. Differential Non-linearity (DNL)
• Quantization Error: Due to the quantization of the input voltage into a finite number of codes, a
• Absolute Accuracy: The maximum deviation of an actual (unadjusted) transition compared to
164A/164PA/324A/324PA/644A/644PA/1284/1284P
between two adjacent transitions) from the ideal code width (1 LSB). Ideal value: 0 LSB.
range of input voltages (1 LSB wide) will code to the same value. Always ±0.5 LSB.
an ideal transition for any code. This is the compound effect of Offset, Gain Error, Differential
Error, Non-linearity, and Quantization Error. Ideal value: ±0.5 LSB.
Output Code
Output Code
0x000
0x3FF
0
1 LSB
V
REF
V
REF
Input Voltage
Input Voltage
Ideal ADC
Actual ADC
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