KST5551 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 160 V
• Collector-Base Voltage, max: 180 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 0.6 A
• Collector Dissipation: 0.35 W
• DC Current Gain (h_fe): 80 to 250
• Transition Frequency, min: 100 MHz
• Noise Figure, max: 8 dB
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: SOT-23
• Electrically Similar to the Popular 2N5551 transistor

Here is an image showing the pin diagram of this transistor.The KST5551 transistor is marked as "G1".The complementary PNP transistor to the KST5551 is the KST5401.The 2N5551 is the TO-92 version of the KST5551.You can replace the KST5551 with the 2N5551S or MMBT5551.