This part is a kind of semiconductor called FMX-G22.
Function of this product has Ultra-Fast-Recovery Rectifier Diodes.
Manufacturers : Sanken electric
Image and pinout :

Some of the text within the PDF file :
Ultra-Fast-Recovery Rectifier Diodes Absolute Maximum Ratings Parameter Type No. VRM (V) I F (AV) (A) With Heatsink IFSM (A) 50Hz Half-cycle Sinewave Single Shot Tj (°C) Tstg (°C) VF (V) max IF (A) IR (mA) Electrical Characteristics (Ta = 25°C) t rr t rr IR (H) (ns) (ns) (mA) IF /IRP (mA) IF /IRP (mA) Others Rth ( j-c) (°C/ W) Mass Fig. (g) VR = VRM VR = VRM max Ta =100°C max FML-G22S FML-G26S FMX-G12S 200 600 10.0 10.0 5.0 150 100 –40 to +150 65 0.98 10.0 1.7 10.0 5.0 0.98 10.0 0.5 0.1 0.1 0.2 2.0 0.3 20.0 40 65 500/500 30 500/1000 500/500 40 500/1000 4.0 100/100 100/200 25 500/500 500/1000 2.1 A 200 30 50 FMX-G22S 10.0 150 FML-G22S TcIF(AV) Derating 10 t /T = 1/2 Average Forward Current I F (AV) (A) Forward Current IF (A) VF IF Characteristics ( [ ... ]
FMX-G22 PDF Datasheet Download
