ULN2803ADWRG4 by Texas Instruments is a peripheral driver with 8 functions, open-collector output, and built-in transient protection. It operates b/w -40 to 85 °C with a max supply voltage of 3 V. Ideal for applications requiring sink current flow direction in a small outline package style.
Diodes Inc.'s BSS138W-7-F is a N-channel FET with 50V DS breakdown voltage, ideal for switching applications. It features single configuration with built-in diode, Gull Wing terminals, and operates in enhancement mode. With 0.2A max drain current and 3.5 ohm RDS(on), it's UL recognized and suitable for small outline packages at temperatures ranging from -55 to 150°C.
ATMEGA328P-AU by Microchip: 8-bit RISC CPU, 20 MHz clock, 23 I/O lines. Ideal for industrial applications with SPI, TWI, USART connectivity and low power mode. Features include 2048 RAM bytes, 1024 EEPROM size, and 16384 ROM words.