9.2.1.1 Inductor Selection

The inductors are L₀, L₁, L₂, and L₃ are shown in theTypical Applications. The inductance and DCR of the inductor affects the control loop of the buck regulator. TI recommends using inductors similar to those listed in Table 10. Pay attention to the saturation current and temperature rise current of the inductor. Check that the saturation current is higher than the peak current limit and the temperature rise current is higher than the maximum expected rms output current. The minimum effective inductance to make sure performance is good is 0.22 μH at maximum peak output current over the operating temperature range. DC resistance of the inductor must be less than 0.05 Ω for good efficiency at high-current condition. The inductor AC loss (resistance) also affects conversion efficiency. Higher Q factor at switching frequency usually gives better efficiency at light load to middle load. Shielded inductors are preferred as they radiate less noise.