This part is a kind of semiconductor called STK402-120.

Function of this product has 2 Channel Class AB Audio Power Amplifier IC.

Manufacturers : Sanyo

Image and pinout :

Some of the text within the PDF file :

Ordering number : ENN7067 w discrete component power amplifier circuits that have a D . Overview w The STK402-000 series products are audio power w amplifier hybrid ICs that consist of optimally-designed been miniaturized using SANYO's unique insulated metal substrate technology (IMST). SANYO has adopted a new low thermal resistance substrate in these products to reduce the package size by about 60% as compared to the earlier SANYO STK407-000 series. S a t e e h U 4 t m o .c Thick-Film Hybrid IC STK402-120 Two-Channel Class AB Audio Power Amplifier IC 80 W + 80 W Package Dimensions unit: mm 4190-SIP15 [STK402-120] 59.2 52.0 16.5 21.0 31.0 Features • Series of pin compatible power amplifiers ranging from 20 W × 2 channels to 120 W × 2 channels (10%/1 kHz) devices. The sam [ ... ]

STK402-120 PDF Datasheet Download