Mixed Signal circuits

It is rare you will find a purely digital or analog circuit in our time. Even FM radios are reduced to integrated circuits that contain both analog and digital elements, and though personal computers are almost entirely digital, certain ways computers communicate with the outside world such as the D-SUB video port use analog. Many of the circuit elements previously mentioned are actually mixed signal devices and employ Analog-to-digital and/or Digital-to-analog conversion. These methods allow circuits to create binary (digital) numbers associated with analog values with varying resolution and approximate analog signals from digital numbers respectively. The Microcontroller is an example of a Mixed-signal integrated circuit which employs both analog and digital techniques. While the computing core is digital, the microcontroller can also deal with analog values by using analog-to-digital converters. Digital cameras are another example as the CCD (Charge Coupled Device) sensor used in most cameras are not digital, but rather analog. The digital portion of the camera is responsible for control, human interface and digital signal processing among other things.