The Texas Instruments ULN2004AD is a power relay array IC with seven NPN bipolar transistors. It is designed to provide a 1:1 ratio of input to output, and is housed in a 16-pin SOIC package. This IC is ideal for applications that require high-current switching, such as motor control, relay control, and lamp control. It features a wide operating voltage range of 4.5V to 18V, and can handle up to 500mA of current per channel. The ULN2004AD also features built-in protection against over-voltage, over-current, and thermal overload. This IC is a reliable and cost-effective solution for applications that require high-current switching.