2SB503A-Y Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -50 V
• Collector-Base Voltage, max: -80 V
• Emitter-Base Voltage, max: -10 V
• Collector Current − Continuous, max: -3 A
• Collector Dissipation: 25 W
• DC Current Gain (h_fe): 100 to 280
• Transition Frequency, min: 5 MHz
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-66

Here is an image showing the pin diagram of this transistor.The 2SB503A-Y transistor can have a current gain of 100 to 280. The gain of the 2SB503A will be in the range from 30 to 280, for the 2SB503A-O it will be in the range from 50 to 140, for the 2SB503A-R it will be in the range from 30 to 70.Sometimes the "2S" prefix is not marked on the package - the 2SB503A-Y might only be marked "B503A-Y".The NZT660 (SOT-223) is the SMD version of the 2SB503A-Y transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SB503A-Y with the 2SA764, 2SB502A or 2SB502A-Y.