Audio amplifier ICs (integrated circuits) are devices used within electronic circuits for audio applications. Audio amplifiers increase, control and amplify the strength or amplitude of the signals. They are used to increase the sound and quality of the audio signal. Amplifier characteristics and performance are classed using letter symbols, such as Class-A, Class-B, Class-C, Class-D or Class-AB.IC audio amplifiers are useful because they can vastly decrease the size of amplification devices, making it possible to create sophisticated amplification within a small package. Unlike power amplifiers, they are not standalone devices. Audio amplifiers come in standard semiconductor packages, such as HTSSOP, MSOP, PDIP, SOIC and TQFN. These packages can be through-hole or surface mounted.Where are Audio Amplifier ICs used?Audio amplifier ICs are used in a range of commercial applications. They are found in car stereos, headphones, televisions, keyboards, and toys. They are also used in electronic circuits for line drivers, ultrasonic drivers, power converters and radio amplifiers.Types of Audio Amplifier:Audio AmplifierAudio Power AmplifierAudio Line DriverAudio SystemBridge AmplifierCompandorMicrophone Pre-AmplifierHeadphone AmplifierSpeaker AmplifierOperational AmplifierThings to consider when choosing an audio amplifier:Input Signal type – This is usually single-ended and/or differential inputs.Output Signal type – This is usually single-ended and/or differential outputs.Maximum Power – Given in watts, depending on the size and scope of amplification you need.Output Type – Mono outputs have a single channel, while stereo outputs have more than one.