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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
+$$D = \frac{{3.3 - 2.304}}{3.3} = 0.302$$