ULN2803A by Texas Instruments is a peripheral driver with 8 functions. It has a max supply voltage of 3V and can operate in temperatures ranging from -40 to 85°C. This IC is commonly used as a buffer or inverter based peripheral driver for various applications.
MMBT2222ALT1G by Onsemi is a NPN BJT transistor with 3 terminals, max power dissipation of 0.3W, and hFE of 75. Ideal for switching applications, it operates b/w -55 to 150 °C with a max collector-emitter voltage of 40V. This surface-mount device has a transition frequency of 300MHz and turn-on time of 35ns.
BSS138LT1G by Onsemi is a N-CHANNEL FET with 50V DS Breakdown Voltage, 0.2A Drain Current, and 3.5 ohm On Resistance. Ideal for SWITCHING applications due to its ENHANCEMENT MODE operation and built-in DIODE. Operates b/w -55 to 150 °C with small outline package style for surface mount assembly.