The MMBT489LT1G is an NPN Transistor manufactured by ON Semiconductor. It has a bipolar (BJT) structure, a 1A continuous collector current, and a 50V max collector-emitter voltage. It is used in applications such as power management, motor and load control, signal switching, signal amplification, and protection circuits. This transistor provides excellent linearity, reduced distortion, and high switching speed. It also has a low saturation voltage, fast switching speed, and low on-resistance for reduced power consumption.