I am doing some math for inductors. The datasheet says I need L (inductance?) such that $L = \frac{V_{BAT} \times (V_{OUT} - V_{BAT})}{\Delta I_L \times \ f \times V_{OUT}}$ Frequency is in the datasheet at 600kHz, I assume I'll have to put that in hertz. Current is the "ripple current" which is 20% of I_L, which is my load current. Let's say... 1.5A for safety sake, but the USB spec has 0.5A $\frac{3.3 \times (5 - 3.3)}{0.2 \times 1.5 \times 600000 \times 3.3} = 9.4 \mu H$ 9.4 nH I can probably work backwards to find out the 6.8 value $ 5.61 / (0.2 x 600000 \cdot 3.3) = 0.0000068$ $5.61 / 0.0000068 = 396000 x $ $x = 2.08A$ Which checks out for a 2A draw, and probably what I should just stick with. But what about all the other descriptions on the inductor? DC Resistance (DCR) is apparently just like loss when near 0Hz, and so lower is better because the loss happens in heat (says [digikey forum post](https://forum.digikey.com/t/choosing-dc-resistance-of-an-inductor/1860)) Adafruit has used [this inductor](https://www.digikey.ca/en/products/detail/tdk-corporation/VLC5045T-6R8M/2465284) with a 2.7A current rating and 46mOhm DCR. But that's for a 500mA powerboost. The 1000mA schematic calls for a 4A, which is probably why I picked the first one I did. How about [this one](https://www.digikey.ca/en/products/detail/kemet/MPXV1D0624L6R8/11314569), it's pricey (relatively speaking), but really high current capacity, relatively OK DCR, but it's also VERY flat. Sadly, no footprint from digikey. [This one](https://www.digikey.ca/en/products/detail/vishay-dale/IHLP2525BDER6R8M01/2574335) has more stock, but worse DCR, but it does have a footprint.