NPN; Configuration: SINGLE; Surface Mount: NO; Nominal Transition Frequency (fT): 300 MHz; Maximum Power Dissipation (Abs): .5 W; Maximum Collector Current (IC): .8 A;
STM32F401CDY6TR by STMicroelectronics is a 32-bit microcontroller with 393216 ROM words, 50 MHz clock frequency, and 36 I/O lines. It is used in applications requiring high-speed processing, such as industrial automation and consumer electronics.
ULN2803ADWR by Texas Instruments is a peripheral driver with 8 functions, open-collector output characteristics, and built-in transient protections. It operates b/w -40 to 85°C, has a max supply voltage of 3V, and is ideal for buffer or inverter-based applications requiring sink current flow direction.