The TIP120 from STMicroelectronics is a Darlington transistor that is ideal for use as a switch or amplifier control device. It features an integrated current gain stage with a monolithic Darlington pair and an integrated collector-emitter saturation voltage regulator. It is housed in an industry standard TO220 package and is rated for 200V and 5A. It is a great choice for switching and amplifier applications, including motor control, light dimming, and other DC current applications.