Keith Szolusha@ edn.com writes:
In certain dc/dc-converter applications, on-chip, cycle-by-cycle current limit may be insufficient protection to prevent a failure during a short circuit. A nonsynchronous boost converter provides a direct path from the input to the short circuit through the inductor and the catch diode. Regardless of current-limit protection in the IC, when a short circuit exists in the load, extremely high currents that flow through the load path can damage the catch diode, the inductor, and the IC. In a SEPIC (single-ended, primary-inductance-converter) circuit, the coupling capacitor breaks this path.
Single transistor provides short-circuit protection – [Link]