Please follow below guidance for the inductors design of TPS923651 / TPS923650:
Boost Configuration:
In a boost regulator, the inductor DC current can be calculated as:
(1)
(2)
Iout is the current go through the LED load.
The inductor ripple current is calculated as:
(3)
(4)
From (1) - (4), we can get:
K is a coefficient that represents the amount of inductor ripple current relative to the inductor DC current.
Fsw is the switching frequency.
Vout:
(1) If you are using the device in Boost connection, Vout refers to the sum of the forward voltage across LED load.
(2) If you are using the device in Buck-Boost connection, Vout refers to the sum of the forward voltage across LED load plus your maximum input voltage.
For example, in TPS923651 datasheet Section 8.2.1.2, Vin = 12V, Vout = 24V, Iout = 1A, Fsw = 400kHz, choose KIND = 0.3, the calculated inductance is (12*12*12) / (24*0.3*400000*1*24) = 25uH.
