This is one of the semiconductor types. This part name is DP904C.
This product has DP904C functions.
Manufacturers of product is ETC.
Image and pinout :
DP904C PDF Datasheet
Some of the text files within the PDF file
Pinout
1. Drain
2. GND
3. Vcc
4. F_B
5. SYNC
[ … ]
Please refer to the file for details.