2SA817 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -80 V
• Collector-Base Voltage, max: -80 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -0.3 A
• Collector Dissipation: 0.6 W
• DC Current Gain (h_fe): 70 to 240
• Transition Frequency, min: 100 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-92

The 2SA817 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.The 2SA817 transistor can have a current gain of 70 to 240. The gain of the 2SA817-O will be in the range from 70 to 140, for the 2SA817-Y it will be in the range from 120 to 240.Sometimes the "2S" prefix is not marked on the package - the 2SA817 might only be marked "A817".The complementary NPN transistor to the 2SA817 is the 2SC1627.The 2SA1620 (SOT-23) is the SMD version of the 2SA817 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SA817 with the 2N5401C, 2SA1275, 2SA1284, 2SA1315, 2SA817A, 2SA984K, 2SB560, 2SB647, KSA1013, KSA709C, KTA1274 or KTA1275.