ATTINY43U-SU Family Name, Microchip ATTINY43U-SU, 8bit AVR Microcontroller, ATtiny43, 8MHz, 4 kB Flash, 20-Pin SOIC

The high-performance, ultra low-voltage 8-bit AVR RISC-based microcontroller combines 4KB flash memory, 64B EEPROM, 256B SRAM, 16 general purpose I/O lines, 32 general purpose working registers, two 8-bit timer/counters with two PWM channels, internal and external interrupts, a 4-channel 10-bit A/D converter, a universal serial interface (USI), programmable watchdog timer with internal oscillator, internal calibrated oscillator, and three software selectable power saving modes. By executing powerful instructions in a single clock cycle, the device achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and processing speed.
Boost Converter: Built-in boost voltage converter providing 3V to the processor while only requiring between 0.7-1.8 volts from its external power supply (1.8-5.5 volts when the voltage converter is bypassed).