ATtiny43U has 4KB of in-system programmable Flash memory, 64B of EEPROM and 256B of SRAM. It has two 8-bit timer-counters, both with two PWM outputs. The timers can be set to run in fast PWM mode with high frequency needed in applications like power regulation, power rectification and in DAC applications. Due to high frequency, the physical size and cost of external components like coils and caps can be kept small. Alternatively the timers can also run in high resolution phase correct mode that is required in applications where a motor is directly controlled by the MCU. The 10-bit ADC is valuable as a battery fuel gauge, but for other analog-to-digital interfacing too. ATtiny43U is equipped with Atmel’s Universal Serial Interface (USI) that can work in two wire mode (I2C compliant) or in SPI mode.