This part is a kind of semiconductor called TA8218AH.

Function of this product has AUDIO POWER AMPLIFIER.

Manufacturers : Toshiba

Image and pinout :

Some of the text within the PDF file :

TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic TA8218AH Audio Power Amplifier TA8218AH The TA8218AH is 3 channel audio amplifier for consumer applications. This IC provides an output power of 6 watts per channel (at VCC = 20 V, f = 1kHz, THD = 10%, RL = 8 Ω). It is suitable for power amplifier of TV and home stereo. Features · Built-in 3ch amplifier · High output power: Pout = 6 W/ch (Typ.) (VCC = 20 V, RL = 8 Ω, f = 1 kHz, THD = 10%) · Low noise: Vno = 0.14 mVrms (Typ.) Weight: 9.8 g (typ.) (VCC = 20 V, RL = 8 Ω, GV = 34dB, Rg = 10 kΩ, BW = 20 Hz~20 kHz) · Built in audio muting circuit (Active → Low) : Main amp/surround amp independent control. · Built in various protection circuits Protection circuit: Thermal shut down, over voltage, Out → GND s [ ... ]

TA8218AH PDF Datasheet Download