2SA643R Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -20 V
• Collector-Base Voltage, max: -40 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -0.5 A
• Collector Dissipation: 0.5 W
• DC Current Gain (h_fe): 40 to 80
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The 2SA643R 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, base, and collector leads.
Here is an image showing the pin diagram of this transistor.The 2SA643R transistor can have a current gain of 40 to 80. The gain of the 2SA643 will be in the range from 40 to 400, for the 2SA643G it will be in the range from 200 to 400, for the 2SA643O it will be in the range from 70 to 140, for the 2SA643Y it will be in the range from 120 to 240.Sometimes the "2S" prefix is not marked on the package - the 2SA643R might only be marked "A643R".The complementary NPN transistor to the 2SA643R is the 2SD261R.The KSA643R is the TO-92 version of the 2SA643R.You can replace the 2SA643R with the KSA643, KSA643R, MPS6533, MPS6535, PN2904 or PN2906.