I'm looking for suggestions on how to control a DC motor with a transistor and a uC. The input voltage is 15vDc and the resistance across the two pins of the motor is 3.3R, so we'll call it 5 amps. The way it was originally controlled was that both pins on the motor had 15v+ (float high) and when rotation was needed, one of the pins would be given a path to ground, presumably through a transistor, and I'd like to do the same.

I started with a TIP120 transistor, however it would get way too hot and I've looked at an IRLZ44, however it appears that will also require heat management. Is there a better option (transistor or another way I haven't thought of) to control this motor without having to worry about heat management? The duty cycle should be minimal, but I'd prefer to overbuild so there is no risk of heat problems. I also do not believe a standard relay is a good alternative due to mechanical life cycle limits and the noise.