2SB559 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -18 V
• Collector-Base Voltage, max: -20 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -1.2 A
• Collector Dissipation: 8 W
• DC Current Gain (h_fe): 60 to 320
• Transition Frequency, min: 150 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-126

Here is an image showing the pin diagram of this transistor.The 2SB559 transistor can have a current gain of 60 to 320. The gain of the 2SB559-D will be in the range from 60 to 120, for the 2SB559-E it will be in the range from 100 to 200, for the 2SB559-F it will be in the range from 160 to 320.Sometimes the "2S" prefix is not marked on the package - the 2SB559 might only be marked "B559".The complementary NPN transistor to the 2SB559 is the 2SD439.You can replace the 2SB559 with the 2SA715, 2SA738, 2SB743, 2SB772, BD186, KSB772, KSH772 or MJE370.