2SA2121 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -200 V
• Collector-Base Voltage, max: -200 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -15 A
• Collector Dissipation: 220 W
• DC Current Gain (h_fe): 55 to 160
• Transition Frequency, min: 25 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-3P

Here is an image showing the pin diagram of this transistor.The 2SA2121 transistor can have a current gain of 55 to 160. The gain of the 2SA2121-O will be in the range from 80 to 160, for the 2SA2121-R it will be in the range from 55 to 110.Sometimes the "2S" prefix is not marked on the package - the 2SA2121 might only be marked "A2121".The complementary NPN transistor to the 2SA2121 is the 2SC5949.You can replace the 2SA2121 with the 2SA1302, 2SA1943, 2SA1962, 2SA1986, 2SA2151, 2SA2151A, 2SA2151A-O, 2SA2151A-P, 2SA2151A-Y, FJA4213, FJL4215, KTA1943, KTA1943A, KTA1962, KTA1962A, MJW1302A, MJW1302AG or NTE2329.