This part is a kind of semiconductor called STK428-640.

Function of this product has 2Ch 150W.

Manufacturers : Sanyo

Image and pinout :

Some of the text within the PDF file :

STK428-640 D 2ch 150W θ ° ° ° ° Ω Ω STK428-640 Ω Ω Ω Ω Ω Ω 78.0 70.0 9.0 5.0 21.0 32.0 3.6 1 2.0 (8.0) 0.5 28 0.4 2.9 5.5 27X2.0=54.0 4.0 25.8 STK428-640 Ω Ω Ω Ω Æ STK428-640 Control Chip OCM 20 ENA 21 5 FBPWM1 TEST 8 Driver Chip1 Voltage Check Global Protection Rec. Soft Limit Current Detect High Drive Current Detect COM/MECC Control Ch1 Comp arator Reciever DeadTime Low Drive 3 VS1 COM/MECC Control Ch2 Comp arator Current Detect High Shift Current Detect Reciever DeadTime Synchro Circuit Thermal Warning Driver Chip2 Low Drive 27 VS2 1 VDR 26 PWM2 4 PWM1 2 VD1 DCG 19 Current Prot / HF Prot 6 ZB1 7 FB1 VDCK 17 VSCK 18 Inverting IN1- 12 AGND1 13 Non-Inverti [ ... ]

STK428-640 PDF Datasheet Download