From bb571fe6950a65d42dc4a03b872ea80cbd256680 Mon Sep 17 00:00:00 2001 From: ben-jaynes <1btjaynes@gmail.com> Date: Wed, 24 Jun 2026 17:41:24 -0700 Subject: [PATCH] vault backup: 2026-06-24 17:41:24 --- PCB Design/Music Player/Process.md | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/PCB Design/Music Player/Process.md b/PCB Design/Music Player/Process.md index ac27fc1..c695aa1 100644 --- a/PCB Design/Music Player/Process.md +++ b/PCB Design/Music Player/Process.md @@ -24,4 +24,14 @@ Now calculating for $I_{PEAK}$ using the values - $\eta = 0.9$ (efficiency assumption stated in datasheet) $$I_{PEAK} = \frac{3.3}{0.9 * (1 - 0.302)} + \frac{{2.304 * 0.302}}{2 * 2.5 * 1.5} = 5.346$$ The datasheet states to pick an inductor with a saturation current 20% higher than the calculated value which would mean $$I_{sat} \geq 6.415$$ -The [EXLA1V0402-1R5-R](https://www.digikey.com/en/products/detail/eaton-electronics-division/EXLA1V0402-1R5-R/16893520) has a saturation current of 6.7A which should be a good value for this application. The DC resistance is also low and comparable to the options listed in the datasheet. \ No newline at end of file +The [EXLA1V0402-1R5-R](https://www.digikey.com/en/products/detail/eaton-electronics-division/EXLA1V0402-1R5-R/16893520) has a saturation current of 6.7A which should be a good value for this application. The DC resistance is also low and comparable to the options listed in the datasheet. +### Output Capacitors +The datasheet states no major considerations except for capacity and being small and ceramic. Either ones I already have or any 22uF ceramic capacitor will be used. +### Input Capacitors +Other than being X5R or X7R no other major considerations are needed for the input capacitors. +### Output Voltage Selection +Since 3.3V are needed the values of 180K and 1M will be used for the feedback voltage divider as stated in the table of common output voltage values in the datasheet. + +| $V_{OUT}$ | $R1$ | $R2$ | +| --------- | ----------- | ------------- | +| 3.3 V | 1 M$\Omega$ | 180 k$\Omega$ |