PN3643 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 30 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 0.625 W
• DC Current Gain (h_fe): 100 to 300
• Transition Frequency, min: 250 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92
• Electrically Similar to the Popular 2N3643 transistor

The PN3643 is manufactured in a plastic TO-92 case. When looking at the flat side with the leads pointed downward, the three leads emerging from the transistor are, from left to right, the emitter, collector, and base leads.
Here is an image showing the pin diagram of this transistor.You can replace the PN3643 with the 2N3704, 2SC1318, 2SC1384, 2SC1959, 2SC2120, 2SC2236, 2SC2274, 2SC2277, 2SC2328A, 2SC2710, 2SC3203, 2SC3205, 2SC3243, 2SC3916, 2SC3917, 2SC3918, 2SC3919, 2SC3920, 2SC3921, 2SC3922, 2SC3923, 2SC3940A, 2SC4208A, 2SD1207, 2SD1347, 2SD1835, 2SD789, 2SD863, KSC1008C, KSC2328A, KSP8098C, KTC1008, KTC3203, KTC3204, KTC3205, KTC3210 or KTD863.