The ULN2003A is an integrated circuit manufactured by Youtai. It is a type of driver with an array of Darlington transistors in a SOP-16 RoHS package. It can be used for driving relay coils, stepping motors, lamps, and LEDs. It is designed to suit the needs of higher voltage and current loads with its larger capacitive loads and higher power switching capability. The ULN2003A has a voltage range from 4.5V to 36V and can switch up to 500mA of current. It also has a wide range of protection features such as over-current protection, ESD, short-circuit, thermal protection, and more.