This part is a kind of semiconductor called TDA7318D.

Function of this product has DIGITAL CONTROLLED STEREO AUDIO PROCESSOR.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

® TDA7318 DIGITAL CONTROLLED STEREO AUDIO PROCESSOR INPUT MULTIPLEXER: - 4 STEREO INPUTS - SELECTABLE INPUT GAIN FOR OPTIMAL ADAPTION TO DIFFERENT SOURCES INPUT AND OUTPUT FOR EXTERNAL EQUALIZER OR NOISE REDUCTION SYSTEM VOLUME CONTROL IN 1.25dB STEPS TREBLE AND BASS CONTROL FOUR SPEAKER ATTENUATORS: - 4 INDEPENDENT SPEAKERS CONTROL IN 1.25dB STEPS FOR BALANCE AND FADER FACILITIES - INDEPENDENT MUTE FUNCTION ALL FUNCTIONS PROGRAMMABLE VIA SERIALI2CBUS DESCRIPTION The TDA7318 is a volume, tone (bass and treble) balance (Left/Right) and fader (front/rear) processor for quality audio applications in car radio and Hi-Fi systems. PIN CONNECTION (Top view) DIP28 SO28 ORDERING NUMBERS: TDA7318 TDA7318D Selectable input gain is provided. Control is accomplished by serial I2C bus microproces [ ... ]

TDA7318D PDF Datasheet Download