Standard drivers suffer from current ripple . As the motor holds a position, the driver switches current on and off rapidly. Cheap drivers produce a jagged sine wave, causing:
When you purchase an FSSM100 labeled "Extra Quality," you are paying for statistical reliability. Standard units might have a Mean Time Between Failures (MTBF) of 50,000 hours; Extra Quality variants often push this past 100,000 hours. Typical specs include: fssm100 driver extra quality