Help choosing a transistor to drive an LED strip from a Raspberry Pi
Do you care if you switch on the high side or the low side? Because if you switch on the low side, a logic-level N-channel FET will interface directly to the 3.3V GPIO of your Raspberry Pi. It will have lower IR drop and thus have less thermal dissipation than a transistor.

A 2N7002 will handle ~200mA by itself. Use two or three in parallel and you have more than enough current to handle the LED strip, and then some. These FETs are very, very cheap. Bonus: no gate resistor needed normally.







simulate this circuit &ndash; Schematic created using CircuitLab

Or, use a single, higher-current FET like the NDS351N (1.1A).

If you want to use high-side drive you will need to translate the switching voltage up. In this case, a different circuit would work:







simulate this circuit