When using an LMD18200 to control a DC motor, will the back EMF generated by the motor damage the LMD18200?
The DC motor will generate back EMF. This is normal and not a problem for the LMD18200 in general. If the load drum has a lot of rotational inertia, however, the back EMF may become a problem if the drum is spinning fast and the system tries to brake or change the direction of the drum abruptly. Assume the drum reaches high speed by having one set of switches ON (e.g., upper left and lower right) for a near 100% duty cycle. The back EMF may reach a voltage near the input supply voltage (depends on the motor characteristics). Braking or changing directions abruptly by swapping the set of ON switches (now upper right and lower left) will abruptly apply a voltage equal to the input supply voltage plus the back EMF across the motor. A load with high rotational inertia will take a long time to slow down (long as in mechanical time constant vs electrical). This means the motor will see the input supply voltage plus the back EMF across its terminals for a long time. This voltage could be clos
