2SD1803-Q Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 50 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 5 A
• Collector Dissipation: 20 W
• DC Current Gain (h_fe): 70 to 120
• Transition Frequency, min: 180 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-251

Here is an image showing the pin diagram of this transistor.The 2SD1803-Q transistor can have a current gain of 70 to 120. The gain of the 2SD1803 will be in the range from 70 to 400, for the 2SD1803-R it will be in the range from 100 to 200, for the 2SD1803-S it will be in the range from 140 to 280, for the 2SD1803-T it will be in the range from 200 to 400.Sometimes the "2S" prefix is not marked on the package - the 2SD1803-Q might only be marked "D1803-Q".The complementary PNP transistor to the 2SD1803-Q is the 2SB1203-Q.You can replace the 2SD1803-Q with the 2SD1804, 2SD1804-Q, KSC3074, KSC3074-O, KTC2022L or KTC2022L-Y.