The integrated soft-start circuit prevents input inrush current impacting the LMR516xx-Q1 and the input power supply. Soft start is achieved by slowly ramping up the internal reference voltage when the device is first enabled or powered up. The typical soft-start time is 2.3ms.

The LMR516xx-Q1 also employs overcurrent protection blanking time, T_{OCP_BLK} (33ms typical), at the beginning of power up. Without this feature, in applications with a large amount of output capacitors and high V_OUT, the inrush current is large enough to trigger the current-limit protection, which can cause a false start as the device enters into hiccup mode. This event results in a continuous recycling of soft start without raising up to the programmed output voltage. The LMR516xx-Q1 is able to charge the output capacitor to the programmed V_OUT by controlling the average inductor current during the start-up sequence in the blanking time, T_{OCP_BLK}.