SLUSCD4B March 2017 – May 2018 TPS543C20
To calculate the value of the output inductor (L), use Equation 5. The coefficient KIND represents the amount of inductor-ripple current relative to the maximum output current. The output capacitor filters the inductor-ripple current. Therefore, selecting a high inductor-ripple current impacts the selection of the output capacitor because the output capacitor must have a ripple-current rating equal to or greater than the inductor-ripple current. Generally, the KIND should be kept between 0.1 and 0.3 for balanced performance. Using this target ripple current, the required inductor size can be calculated as shown in Equation 5.
A standard inductor value of 470 nH is selected. For this application, Wurth 744309047 was used from the web-orderable EVM.