Any circuits that have more than the most basic of functions requires a little black chip known as an integrated circuit. Integrated circuits, or ICs, fall into 3 categories, analog, digital, or mixed signal. Analog signals can vary in the entire range between the minimum and maximum signals. In the case of this graphic, any voltages between 0V and 5V.Digital signals are typically on or off, high or low, represented by a 1 or 0. Analog ICs are most commonly used for regulation or amplification. Since sound, voice, and music signals are typically analog, they frequently make use of analog ICs. Digital signals, being much simpler as only having two states, allow for the sending and storing of data much more easily and efficiently. Some ICs have components that allow the conversion of analog and digital signals from one to another. These are known as mixed-signal ICs. Follow along to learn about voltage regulators, op-amps, logic gates, 555 timers, microcontrollers, ROM, RAM, and more.