For bipolar motors upto 2-3 amp/phase there are a lot of different full bridges amplifiers, drivers or integrated components, upto 5A we can use a couple of L6203 (for instance), but for bigger motors, very probably, an external full bridge mosfet driver has to be considered a must.
Here follows a schematic regarding a full bridge driver made by single mosfets to be connected to an L297 (or similar).
