From 4c7dc9473ae3df6c1f3f3b5553b778aa9e0070d4 Mon Sep 17 00:00:00 2001
From: ben-jaynes <1btjaynes@gmail.com>
Date: Wed, 24 Jun 2026 17:11:15 -0700
Subject: [PATCH] vault backup: 2026-06-24 17:11:15

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 PCB Design/Music Player/Process.md | 17 +++++++++++++++++
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+#pcb/musicplayer #pcb 
+- - -
+
+## TPS63020
+### Choosing an Inductor
+The equations needed to find the peak current in steady state operation are 
+Duty cycle boost: $$D=\frac{{V_{OUT} - V_{IN}}}{V_{OUT}}$$
+and peak current: $$I_{PEAK} = \frac{I_{out}}{\eta * (1 - D)} + \frac{{V_{IN} * D}}{2 * f * L}$$
+where 
+- $D$ = duty cycle in boost mode
+- $f$ = converter switching frequency
+- $L$ = inductor value
+- $\eta$ = estimated converter efficiency
+(This is taken from section 8.2.2.2 of the datasheet)
+
+First, to calculate the duty cycle boost we can plug in the output voltage (3.3V) and the "minimum input voltage in boost mode" which for the BQ25985 is listed as 2.304V
+$$D = \frac{{3.3 - 2.304}}{3.3} = 0.302$$