Some motors with small L-R time constants additionally will suffer from poor current regulation when the current in the load is increasing in magnitude due to the slow decay mode. When trying to regulate to a very low current the minimum on-time of 1µs can result in an average current that has a magnitude larger than zero. The minimum on-time is the time required to blank the current sense comparator so false tripping does not occur due to switching transients and reverse recovery of the body diodes. The A498x series has an additional setting to prevent this.