MP2341 Inductor Value?

I’d like to use the MP2341 to drive a single high-powered LED, maximum current is 2A at 3V. It will be powered by 5V. Using Equation 2 on page 14 of the datasheet, I’m calculating 2uH for the needed inductor - however, since the data sheet contains inductor recommendations only from 4.7-15uH, which are all higher than my calculation, I suspect that my calculation might be wrong.

Here’s what I’m using for values:

  • Vin = 5V
  • Vout = 3V
  • Max load current = 2A
  • Max inductor ripple current = 0.6A (2.0 * 0.3)
  • fsw = 1MHz (1e6)

I’d appreciate if someone can let me know if my calculation is incorrect, or if 2uH is actually an expected result. Thanks.

Hi ,
The value you have calculated is correct - its a theoretical value to compare with and a good starting point. Typically, with inductor and ripple current, its a balancing act depending on your application. The device you have chosen to evaluate is great on efficiency, therefore slightly higher inductor value would give better output results.

The inductor value you have calculated will possibly work best within that parameters you have listed. In order to allow for extra margin - you may also try slightly higher input voltages, vary output voltage level, and lower inductor ripple current window, like 10% instead of 30%.

We have recommended inductors to help with component selection, you may use inductors from other vendors and compare too.


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