2SA1721-O Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -300 V
• Collector-Base Voltage, max: -300 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -0.1 A
• Collector Dissipation: 0.15 W
• DC Current Gain (h_fe): 50 to 150
• Transition Frequency, min: 55 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: SOT-23

Here is an image showing the pin diagram of this transistor.The 2SA1721-O transistor can have a current gain of 50 to 150. The gain of the 2SA1721 will be in the range from 30 to 150, for the 2SA1721-R it will be in the range from 30 to 90.Sometimes the "2S" prefix is not marked on the package - the 2SA1721-O might only be marked "A1721-O".The complementary NPN transistor to the 2SA1721-O is the 2SC4497-O.You can replace the 2SA1721-O with the FMMTA92, KST92, MMBTA92 or PMBTA92.