Popular transistors.

AO3400 MOSFET transistor.
Pinout. Datasheet.

Package: TO-23
Marking code: A09T.
Type of AO3400 transistor: MOSFET
Type of control channel: N - Channel
Maximum power dissipation (PD): 0,9W
Maximum drain-source voltage (VDSS): 30V
Maximum gate-source voltage (VGS): ±12V
Maximum continuous drain current (ID):4,9A
Maximum pulsed drain current (IDM):30 A
Maximum junction temperature (Tj): 150?C
Rise Time (tR):2,5ns
Input Capacitance (Ciss):630 pF
Output Capacitance (Coss):75 pF
Maximum drain-source on-state resistance (RDS): 0.018 - 0.028 Ohm
Forward Transconductance(gfs):33
AO3400 Datasheet (PDF)