2SA643Y 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): 120 to 240
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The 2SA643Y 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 2SA643Y transistor can have a current gain of 120 to 240. 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 2SA643R it will be in the range from 40 to 80.Sometimes the "2S" prefix is not marked on the package - the 2SA643Y might only be marked "A643Y".The complementary NPN transistor to the 2SA643Y is the 2SD261Y.The KSA643Y is the TO-92 version of the 2SA643Y.You can replace the 2SA643Y with the 2N4403, 2SA695, 2SB564A, 2SB564AY, KN2907, KSA643, KSA643Y, KSB564A, KSB564AY, KTC8550, KTC9012, KTN2907, M8550, MPS2907, MPS2907G, MPS3702, MPS6534, MPS6535, MPS6651, MPS6651G, MPS6652, MPS6652G, MPS750, MPS750G, MPS8550, MPSW51, MPSW51A, MPSW51AG, MPSW51G, PN2905, PN2907, S8550, S9012, SS8550, ZTX549, ZTX948 or ZTX949.