The MMBT5551 is an NPN transistor, manufactured by Semtech, with a power rating of 600mA and a voltage rating of 160V. It comes in a SOT-23-3 package that is compliant with RoHS regulations. This small and low-profile transistor is used for controlling, amplifying, and switching a variety of low-power electronic circuits. Its features include an oscillator, amplifier, switch, and high-frequency signal amplifier. This transistor is widely used in low-voltage and medium-power applications such as computer peripherals, consumer electronics, ATM machines, and automotive electronics. It is also ideal for digital applications. This reliable and high-performance device is available in bulk quantities, allowing designers to take advantage of its low cost.