7.4.3 Hiccup-Mode Overload Protection

If cycle-by-cycle current limit is reached during any cycle, a 30-μA current is sourced into the RES capacitor for the remainder of the clock cycle. If the RES capacitor voltage exceeds the 1.2-V restart threshold, a hiccup mode over load protection sequence is initiated; The SS capacitor is discharged to GND, both LO and HO outputs are disabled, the voltage on the RES capacitor is ramped up and down between 2-V hiccup counter lower threshold and 4-V hiccup counter upper threshold eight times by 10-μA charge and 5-μA discharge currents. After the eighth cycles, the SS capacitor is released and charged by the 10-μA soft-start current again. If a 3-V zener diode is connected in parallel with the RES capacitor, the regulator enters into the hiccup-mode off mode and then never restarts until UVLO shutdown is cycled. Connect RES pin directly to the AGND when the hiccup-mode operation is not used.

Figure 26. Hiccup Mode Overload Protection