SNVS788H January 2012 – August 2021 LM5019
The inductance selection is a compromise between solution size, output ripple, and efficiency. The peak inductor current at maximum load current must be smaller than the minimum current limit threshold of 150 mA. The maximum permissible peak-to-peak inductor ripple is determined by Equation 10.
The minimum inductance is determined by Equation 11.
Using maximum VIN of 95 V, the calculation from Equation 11 results in L = 203 μH. A standard value of 220 μH is selected. With this value of inductance, peak-to-peak minimum and maximum inductor current ripple of 27 mA and 92 mA occur at the minimum and maximum input voltages, respectively. For robust short circuit protection, the inductor saturation current should be higher than the maximum current limit threshold of 300 mA.