The MMBT3904 is a high-performance NPN bipolar transistor, commonly used for switching and amplifying electronic signals in many types of applications. It is manufactured by Chinese semiconductor company Pingjingsemi and comes in SO-T23 RoHS form. It has maximum current rating of 200mA, maximum VCE/VCS rating of 30V, and a maximum power dissipation of 625mW. Its features include low noise, high unity gain frequency (fT) of 200 MHz, a typical hFE of 230, and an extraordinary gain bandwidth product of 10MHz. This versatile, high-performance transistor is widely used in low-voltage circuitry.