This part is a kind of semiconductor called STK433-320-E.
Function of this product has 3-channel class AB audio power IC.
Manufacturers : Sanyo Semicon Device
Image and pinout :
Some of the text within the PDF file :
Ordering number : EN*A1630 Thick-Film Hybrid IC STK433-290-E Overview 3-channel class AB audio power IC, 80W+80W+80W The STK433-290-E is a hybrid IC designed to be used in 80W × 3ch class AB audio power amplifiers. Applications • Audio power amplifiers. Features • Pin-to-pin compatible outputs ranging from 80W to 150W. • Can be used to replace the STK433-000/-100 series (30W to 150W × 2ch) and STK433-200(A) series (30W to 60W × 3ch) due to its pin compatibility. • Miniature package (64.0mm × 36.6mm × 9.0mm) • Output load impedance: RL = 6Ω to 4Ω supported • Allowable load shorted time: 0.3 second • Allows the use of predesigned applications for standby and mute circuits. Series Models STK433-290-E Output 1 (10%/1kHz) Output 2 (0.4%/20Hz to 2 [ ... ]