There are three major categories of motors; stepper motors, the brushless DC (BLDC) motor, and the brushed DC motor. Each type of motor features a different topology, which determines how many driver gates are needed. The requirement for the stepper motors is a dual H-bridge, for the BLDC a three-phase bridge, and for the DC motor one H-bridge if bidirectional or a half bridge if unidirectional. ST has a different driver for each type of motor, therefore the customer must know how to chose the proper part.