Specifications:

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: 23
Program Memory Size: 8KB (4K x 16)
Program Memory Type: FLASH
EEPROM Size: 512 x 8
RAM Size: 1K x 8
Voltage - Supply (Vcc/Vdd): 1.8V ~ 5.5V
Data Converters: A/D 6x10b
Oscillator Type: Internal
Operating Temperature: -40°C ~ 85°C (TA)
Mounting Type: Through Hole
Package / Case: 28-DIP (0.300", 7.62mm)
Supplier Device Package: 28-PDIP