Darlington Transistors, the Benefits and Downfalls of Using These Devices with Microcontrollers

Darlington transistors are a couple of transistors connected together. The benefit of using a darlington transistor over a standard transistor is the higher beta value. The higher beta value allows a very small amount of current to control the transistors. In the case of a darlington transistor that controls a 2 amp load would only require a 2mA (milliamp) load from the microcontroller. It is recommended only to switch medium current loads, like up to 3 amps as the voltage drop is high with darlington transistors. If higher current loads are needed to be switched, use a mosfet rather than a darlington transistor.