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I'm working on a few projects where I'll be driving about 8 WS2812B LEDs on a 5V rail with an ATTiny85 (I think the whole circuit is going to draw about .5A; I'm using .75A for my calculations). I'm planning to power this with a lithium ion battery with a nominal voltage of 3.6 volts.

I need to boost the voltage to 5V. I'm considering using the XC9142B50DMR-G step-up converter to do this.

On page 11 of the datasheet (an image is included below), they have a reference implementation and specs for the other components. There seem to be two options for the oscillation frequency: 1.2MHz and 3.0MHz. I can't figure out why I'd prefer one frequency over the other.

One difference appears to be a lower supply current. What does that mean (and if it's an advantage or a disadvantage)? Are there other reasons I'd prefer one frequency to the other?

They also have 2 recommended capacitors but mouser doesn't have them in stock. Can I use any ceramic capacitors that are 10uF and at 10V and an X7T dialectric?

Here's the reference circuit and BOM specs: enter image description here

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    \$\begingroup\$ The inductor has nothing to do with the switching frequency; that's internal to the chip and I can't find anything in the datasheet about how to select it--it might be an option when you order the chip. \$\endgroup\$ – Hearth Jan 31 at 3:09
  • \$\begingroup\$ @Hearth, ohhhhhhh! Thanks!! Well, I suppose my questions are still still roughly the same. I'll update the question. Thank you! \$\endgroup\$ – D. Patrick Jan 31 at 3:18
  • \$\begingroup\$ @SunnyskyguyEE75 Okay, maybe "nothing to do with" was an oversimplification, but the datasheet does mention an internal oscillator used to generate the switching frequency. \$\endgroup\$ – Hearth Jan 31 at 14:03
  • \$\begingroup\$ Yes f is internal and L=dt*V/dI external \$\endgroup\$ – Sunnyskyguy EE75 Jan 31 at 14:20
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I can't figure out why I'd prefer one frequency over the other.

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One difference appears to be a lower supply current. What does that mean (and if it's an advantage or a disadvantage)? Are there other reasons I'd prefer one frequency to the other?

Actually I cannot say anything about the "supply current vs switching frequency" thing. But the only thing I can say is "The higher the switching frequency, the smaller the power inductor". Which means that higher switching frequency helps saving more space.

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High frequency PWM choices means there are good reasons for these options and one must be aware of requirements for;

-cost, of components, qty, size, performance, EM unintended interference, switching loss, temperature rise trade offs when pushing power out to the limits that constrain these.

Unless you have these requirements, it may not matter to you but L affects dI/t for a given voltage.

But as in life there are tradeoffs with size, efficiency and unintended emissions.

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