2SA1803 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -80 V
• Collector-Base Voltage, max: -80 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -6 A
• Collector Dissipation: 55 W
• DC Current Gain (h_fe): 55 to 160
• Transition Frequency, min: 30 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 2SA1803 transistor can have a current gain of 55 to 160. The gain of the 2SA1803O will be in the range from 80 to 160, for the 2SA1803R it will be in the range from 55 to 110.Sometimes the "2S" prefix is not marked on the package - the 2SA1803 might only be marked "A1803".The complementary NPN transistor to the 2SA1803 is the 2SC4688.The BDP952 (SOT-223) is the SMD version of the 2SA1803 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the 2SA1803 with the 2SA1093, 2SA1102, 2SA1103, 2SA1104, 2SA1105, 2SA1106, 2SA1146, 2SA1186, 2SA1263, 2SA1263-O, 2SA1264, 2SA1264-O, 2SA1264N, 2SA1264N-O, 2SA1265, 2SA1265-O, 2SA1301, 2SA1303, 2SA1386, 2SA1489, 2SA1490, 2SA1491, 2SA1693, 2SA1694, 2SA1695, 2SA1804, 2SA1805, 2SA1939, 2SA1940, 2SA1941, 2SA1942, 2SB686, 2SB688, 2SB695, 2SB778, 2SB863, BD246B, BD246C, BD250B, BD250C, BDV94, BDV96, FJA4210, KTB688, KTB688B, KTB778 or TIP36CA.