7.3.4 Switch Current Limit and Short Circuit Protection (HICCUP)

The switch current limit prevents the device from high inductor current and from drawing excessive current from the battery or input voltage rail. Excessive current might occur with a shorted or saturated inductor or a over load or shorted output circuit condition. If the inductor current reaches the threshold I_LIM, the high-side MOSFET is turned off and the low-side MOSFET is turned on to ramp down the inductor current with an adaptive off-time.

When this switch current limits is triggered 32 times, the device reduces the current limit for further 32 cycles and then stops switching to protect the output. The device then automatically start a new startup after a typical delay time of 500 μs has passed. This is named HICCUP short circuit protection. The devices repeat this mode until the high load condition disappears. HICCUP protection is also enabled during the startup.