MJE521 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 40 V
• Collector-Base Voltage, max: 40 V
• Emitter-Base Voltage, max: 4 V
• Collector Current − Continuous, max: 2 A
• Collector Dissipation: 40 W
• DC Current Gain (h_fe): 40
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-126

Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the MJE521 is the MJE371.The 2SC2873 (SOT-89), 2SC2873-O (SOT-89), 2SC2873-Y (SOT-89), BCP54 (SOT-223), BCP54-10 (SOT-223), BCP54-16 (SOT-223), BCX54 (SOT-89), BCX54-10 (SOT-89), BCX54-16 (SOT-89), FMMT491A (SOT-23) and FMMT619 (SOT-23) is the SMD version of the MJE521 transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.You can replace the MJE521 with the 2N6037, 2N6037G, 2N6038, 2N6038G, 2N6039, 2N6039G, 2SC2270, 2SC2270-A, 2SC2270-B, 2SC2270-C, 2SC2877, 2SC2877-O, 2SC2877-Y, 2SC3420, 2SC3420-BL, 2SC3420-GL, 2SC3420-Y, 2SC3422, 2SC3422-O, 2SC3422-Y, 2SC3785, 2SC3786, 2SC3808, 2SD1348, 2SD1348-R, 2SD1348-S, 2SD1348-T, 2SD1348-U, 2SD1509, 2SD1682, 2SD1682-R, 2SD1682-S, 2SD1682-T, 2SD1682-U, 2SD1683, 2SD1683-R, 2SD1683-S, 2SD1683-T, 2SD1683-U, 2SD1722, 2SD1722-Q, 2SD1722-R, 2SD1722-R, 2SD1722-S, 2SD1723, 2SD1723-Q, 2SD1723-R, 2SD1723-R, 2SD1723-S, 2SD794, 2SD794-O, 2SD794-R, 2SD794-Y, 2SD794A, 2SD794A-O, 2SD794A-R, 2SD794A-Y, BD175, BD175-10, BD175-16, BD175-6, BD177, BD177-10, BD177-6, BD179, BD179-10, BD179-6, BD179G, BD187, BD189, BD233, BD233G, BD235, BD235G, BD237, BD237G, BD375, BD375-10, BD375-16, BD375-25, BD375-6, BD377, BD377-10, BD377-16, BD377-25, BD377-6, BD379, BD379-10, BD379-16, BD379-25, BD379-6, BD439, BD439G, BD441, BD441G, BD675, BD675A, BD675AG, BD675G, BD677, BD677A, BD677AG, BD677G, BD679, BD679A, BD679AG, BD679G, BD775, BD777, BD779, BD785, BD787, BD787G, BD789, BDX35, BDX36, BDX37, KSD794, KSD794-O, KSD794-R, KSD794-Y, KSD794A, KSD794A-O, KSD794A-R, KSD794A-Y, KSE180, KSE181, KSE182, KSE800, KSE801, KSE802, KSE803, KTC2814, KTC2814-O, KTC2814-Y, MJE180, MJE180G, MJE181, MJE181G, MJE182, MJE182G, MJE220, MJE221, MJE223, MJE224, MJE240, MJE241, MJE521G, MJE800, MJE800G, MJE801, MJE801G, MJE802, MJE802G, MJE803 or MJE803G.The MJE521G transistor is the lead-free version of the MJE521.