The internal switch turns on until the inductor current reaches the typical dc current limit (ILIM) of 400 mA (TPS61040) or 250 mA (TPS61041). Due to the internal propagation delay of typical 100 ns, the actual current exceeds the dc current limit threshold by a small amount. The typical peak current limit can be calculated:
The higher the input voltage and the lower the inductor value, the greater the peak.
By selecting the TPS6104x, it is possible to tailor the design to the specific application current limit requirements. A lower current limit supports applications requiring lower output power and allows the use of an inductor with a lower current rating and a smaller form factor. A lower current limit usually has a lower output voltage ripple as well.