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.
MMBT3906LT1G by Onsemi is a PNP BJT with VCEsat of 0.4V, hFE of 30, and fT of 250MHz. Ideal for small signal applications in electronics due to its low power dissipation, high transition frequency, and compact SOT-23 package. Suitable for use in temperature-sensitive environments with an operating range from -65°C to 150°C.
NPN; Configuration: SINGLE; Surface Mount: NO; Nominal Transition Frequency (fT): 300 MHz; Maximum Power Dissipation (Abs): .5 W; Maximum Collector Current (IC): .8 A;
TEMPERATURE SENSOR,SWITCH/DIGITAL OUTPUT,SERIAL; Mounting Feature: SURFACE MOUNT; No. of Terminals: 8; Package Shape or Style: RECTANGULAR; Body Width: 3.9 inch; Maximum Supply Voltage: 5.5 V;