This part is a kind of semiconductor called YD1028.

Function of this product has 18W CAR RADIO POWER AMPLIFIER.

Manufacturers : Wuxi Youda electronics

Image and pinout :

Some of the text within the PDF file :

YOUDA INTEGRATED CIRCUIT YD1028 18W CAR RADIO POWER AMPLIFIER—YD1028 DESCRIPTION The YD1028 is an integrated class-B dual output amplifier in a 9-lead single in-line (TO220Z9) plastic power package. The device is primarily developed for car radio applications. FEATURES *Requires very few external components for Bridge Tied Load (BTL),Stereo or BTL application; *High output power, Fixed gain, Good ripple rejection; * Identical inputs (inverting and non-inverting),Low offset voltage at output (important for BTL); *Mute/stand-by switch, No switch-on/switch-off plop; *Load dump protection, AC and DC short-circuit-safe to ground and Vcc, Thermally protected; *Reverse polarity safe; *Capability to handle high energy on outputs (Vcc=0V); *Protected against electrostatic [ ... ]

YD1028 PDF Datasheet Download