The STMicroelectronics TIP125 is a PNP bipolar Darlington Transistor, capable of operating up to 60 volts and 5 amps, or 65 watts of power in a single TO220 AB package. This type of transistor has two collector-base junctions connected in series and can provide a current gain of up to 1000 times that of a single transistor. This makes it ideal for switching high power loads, such as motors, solenoids, and lamps, or even medium power audio amplifiers. The TIP125 also has a high input impedance, making it capable of conditioning weak signals. This makes it useful for RF circuits, as well as in audio preamplifier circuits.