2SA1804 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -120 V
• Collector-Base Voltage, max: -120 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -8 A
• Collector Dissipation: 70 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 2SA1804 transistor can have a current gain of 55 to 160. The gain of the 2SA1804-O will be in the range from 80 to 160, for the 2SA1804-R it will be in the range from 55 to 110.Sometimes the "2S" prefix is not marked on the package - the 2SA1804 might only be marked "A1804".The complementary NPN transistor to the 2SA1804 is the 2SC4689.You can replace the 2SA1804 with the 2SA1093, 2SA1104, 2SA1105, 2SA1106, 2SA1146, 2SA1186, 2SA1264, 2SA1264-O, 2SA1264N, 2SA1264N-O, 2SA1265, 2SA1265-O, 2SA1301, 2SA1302, 2SA1303, 2SA1386, 2SA1386A, 2SA1386A-O, 2SA1386A-P, 2SA1386A-Y, 2SA1490, 2SA1491, 2SA1492, 2SA1516, 2SA1694, 2SA1695, 2SA1805, 2SA1940, 2SA1941, 2SA1942, 2SA1943, 2SA1986, 2SA2120, 2SA2121, 2SA2151, 2SA2151A, 2SA2151A-O, 2SA2151A-P, 2SA2151A-Y, 2SB1429, 2SB688, 2SB778, 2SB863, FJA4210, KTA1943, KTA1943A, KTA1962, KTA1962A, KTB688, KTB688B, KTB778, MJW1302A, MJW1302AG or NTE2329.