BD644 Bipolar Transistor

• Type: PNP
• Collector-Emitter Voltage, max: -45 V
• Collector-Base Voltage, max: -45 V
• Emitter-Base Voltage, max: -5 V
• Collector Current − Continuous, max: -8 A
• Collector Dissipation: 62.5 W
• DC Current Gain (h_fe): 750
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-220

Here is an image showing the pin diagram of this transistor.The complementary NPN transistor to the BD644 is the BD643.You can replace the BD644 with the 2N6040, 2N6040G, 2N6041, 2N6041G, 2N6667, 2N6667G, 2N6668, 2N6668G, 2SB1225, 2SB882, 2SB951, 2SB951-P, 2SB951-Q, 2SB951A, 2SB951A-P, 2SB951A-Q, BD646, BD648, BD896, BD896A, BD898, BD898A, BD900, BD900A, BDT62, BDT62A, BDT64, BDT64A, BDW44, BDW45, BDW46, BDW46G, BDW74, BDW74A, BDW74B, BDW94, BDW94A, BDW94B, BDX34, BDX34A, BDX34B, BDX34BG, BDX54, BDX54A, BDX54B, BDX54BG, TIP105, TIP105G, TIP106, TIP106G, TIP135, TIP135G, TIP136, TIP136G, TIP145T or TIP146T.