BSS138-TP by Micro Commercial Components is a N-channel small signal FET with a min DS breakdown voltage of 50V and max drain current of 0.22A. It is commonly used in applications requiring enhancement mode operation, such as power management and switching circuits.
MMBT3904LT1G by Onsemi is a NPN BJT with max. collector-emitter voltage of 40V, hFE of 30, and fT of 300MHz. Ideal for small signal applications in electronics due to its compact size, high transition frequency, and low power dissipation capabilities.
Small Signal Bipolar Transistors; Configuration: SINGLE; Surface Mount: NO; Nominal Transition Frequency (fT): 300 MHz; Maximum Collector Current (IC): .8 A; JESD-609 Code: e0;