Many microcontrollers contain internal on-chip ADC. Typical devices would be Atmel Atmega series microcontrollers like Atmega8 and further. Internal ADC is a successive way to integrate the analog world into your embedded systems using only one microcontroller die. Many applications don’t require high speed or high accuracy ADC conversions; thus, on-chip ADC is the best choice. Let’s look at Atmega8. It contains a 10-bit approximation ADC with an analog input multiplexer of 8-single-ended input voltage (refers to 0V) channels.