The ATMEGA168-20PU is a 8-bit high-performance, low-power AVR RISC-based Microcontroller Unit combines 16kB ISP flash memory, 1kB SRAM, 512B EEPROM, an 8-channel/10-bit A/D converter (TQFP and QFN/MLF) and debugWIRE for on-chip debugging. The device supports a throughput of 20 MIPS at 20MHz and operates between 2.7 to 5.5V. The current consumption is a function of several factors such as operating voltage, operating frequency, loading of I/O pins, switching rate of I/O pins, code executed and ambient temperature. The dominating factors are operating voltage and frequency. The difference between current consumption in power-down mode with watchdog timer enabled and power-down mode with watchdog timer disabled represents the differential current drawn by the watchdog timer.