In addition to the cycle-by-cycle current limit function, the TPS61378-Q1 also has output short protection.

During normal working condition, when output draws an excessive amount of current, causing the low-side FET to reach peak current limit and the output voltage is pulled below the input voltage, the device enters short circuit protection mode, triggering the hiccup timer. When the hiccup timer is active, the device limits the current for 1.8 ms and then shuts down. After 67 ms, it restarts.

During start-up, whether normal start-up or hiccup restart, the device can trigger short protection. The device has limited loading capacity at start up phase because of smaller peak current limit, which is list in Table 7-1.

Starting up with heavy load or very large capacitors at output side may causes short hiccup protection.