KST4401 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 40 V
• Collector-Base Voltage, max: 60 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 0.6 A
• Collector Dissipation: 0.35 W
• DC Current Gain (h_fe): 100 to 300
• Transition Frequency, min: 250 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: SOT-23
• Electrically Similar to the Popular 2N4401 transistor

Here is an image showing the pin diagram of this transistor.The KST4401 transistor is marked as "2X".The complementary PNP transistor to the KST4401 is the KST4403.The 2N4401 is the TO-92 version of the KST4401.You can replace the KST4401 with the BCW66, FMMT2222A, FMMT2222AR, FMMT491, FMMT491Q, FMMT619, KN2222AS, KST2222A, KTN2222AS, MMBT2222A, MMBT4401, PMBT2222A, PMBT4401 or PMST2222A.