This part is a kind of semiconductor called 2N4990.

Function of this product has Silicon unilateral switch (SUS) in package TO-92.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

2N4990 Silicon unilateral switch (SUS) in package TO-92 0.7max 0.45max 1 2.5 5.2 2 14.5 1.6 4.2 5.2 3 Pinouts: 1- Cathode, 2- Gate, 3- Anode Ratings Symbol Vrrm IT(rms) Igm IT(sm) P Parameter, units Peak reverse voltage, V DC forward anode current, mA DC gate current, mA Peak recurrent forward current, A, (1% duty cycle, 10µsec pulse width) Power dissipation, mW Limits -30 175 5 1 300 Electrical Characteristics (TA=25°C) Symbol VS IS IH IR IB VF Parameter, unit, test conditions Switching voltage, V Switching current, µA Holding current, mA Revers current, µA, VR=-30V Forward current (off-state), µA, VF=5V On-State voltage, V, IF=175mA Limits min max 7 9 200 0.75 0.1 0.1 1.5 Planeta Electronic company JSC Planeta, 2/13, Fedorovsky Ruchei, Veliky Novgorod, 173004, Russia [ ... ]

2N4990 PDF Datasheet Download