ATMEGA16U4-AU Family Name, Microchip ATMEGA16U4-AU, 8bit AVR Microcontroller, ATmega, 16MHz, 16 kB Flash, 44-Pin TQFP

The low power, high performance Microchip 8-bit AVR RISC-based microcontroller featuring 16KB ISP flash memory, 8KB boot code section, 2.5KB SRAM, 1024-byte EEPROM, USB 2.0 full-speed/low speed device, high-speed PWMs, 12-channel 10-bit A/D-converter, and JTAG interface for on-chip-debug. The device achieves up to 16 MIPS throughput at 16MHz. 2.7 - 5.5V operation.
High Performance, Low Power AVR®8-Bit MicrocontrollerAdvanced RISC Architecture135 Powerful Instructions – Most Single Clock Cycle Execution32 x 8 General Purpose Working RegistersFully Static OperationUp to 16 MIPS Throughput at 16MHzOn-Chip 2-cycle MultiplierNon-volatile Program and Data Memories16/32KB of In-System Self-Programmable Flash1.25/2.5KB Internal SRAM 512Bytes/1KB Internal EEPROM Write/Erase Cycles: 10,000 Flash/100,000 EEPROMData retention: 20 years at 85C/ 100 years at 25C Optional Boot Code Section with Independent Lock Bits