The device has a fixed, cycle-by-cycle negative current limit. Similar with the positive overcurrent limit, the inductor current is monitored during the on time of the low-side FET. To prevent too large negative current flowing through low-side FET, when the low-side FET detects –10-A current (typical threshold), the device turns off low-side FET and then turns on high-side FET for a proper on time (determined by V_IN/V_O/f_SW). After high-side FET on time expires, the low-side FET turns on again.

The device must not trigger the –10-A negative current limit threshold during nominal operation, unless a too small inductor value is chosen or the inductor becomes saturated. This negative current limit is used to discharge output capacitors during an output OVP or an OOB event. See Section 7.3.12 and Section 7.3.13 for details.