This part is a kind of semiconductor called W20NK50Z.

Function of this product has STW20NK50Z.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

STP20NK50Z - STW20NK50Z N-CHANNEL 500V - 0.23Ω - 20A TO-220/TO-247 Zener-Protected SuperMESH™Power MOSFET TARGET DATA TYPE STP20NK50Z STW20NK50Z s s s s s s VDSS 500 V 500 V RDS(on) < 0.27 Ω < 0.27 Ω ID 20 A 20 A Pw 190 W 190 W TYPICAL RDS(on) = 0.23 Ω EXTREMELY HIGH dv/dt CAPABILITY 100% AVALANCHE TESTED GATE CHARGE MINIMIZED VERY LOW INTRINSIC CAPACITANCES VERY GOOD MANUFACTURING REPEATIBILITY 3 2 1 TO-220 TO-247 DESCRIPTION The SuperMESH™ series is obtained through an extreme optimization of ST’s well established stripbased PowerMESH™ layout. In addition to pushing on-resistance significantly down, special care is taken to ensure a very good dv/dt capability for the most demanding applications. Such series complements ST full range of high voltage MOSFETs includ [ ... ]

W20NK50Z PDF Datasheet Download