8.4.4 Current Limit and Short Circuit Protection

The peak switch current of TPS6282x is internally limited, cycle by cycle, to a maximum dc value as specified in Electrical Characteristics. This prevents the device from drawing excessive current in case of externally caused over current or short circuit condition. Due to an internal propagation delay of about 60ns, the actual ac peak current can exceed the static current limit during that time.

If the current limit threshold is reached, the device delivers its maximum output current. Detecting this condition for 32 switching cycles (about 13µs), the device turns off the high-side MOSFET for about 100µs which allows the inductor current to decrease through the low-side MOSFET's body diode and then restarts again with a soft start cycle. As long as the overload condition is present, the device hiccups that way, limiting the output power.