The TPS6287x-Q1 devices have been optimized for inductors in the range 50 nH to 300 nH. If the transient response of the converter is limited by the slew rate of the current in the inductor, using a smaller inductor can improve performance. However, the output ripple current increases as the value of the inductor decreases, and higher output current ripple generates higher output voltage ripple, which adds to the transient overshoot or undershoot. The optimal configuration for a given application is always a trade-off between a number of parameters. A starting value of 110 nH for typical applications is recommended.
The peak-to-peak inductor current ripple is given by:
Table 10-2 lists a number of inductors suitable for use with this application. This list is not exhaustive and other inductors from other manufacturers can also be suitable.
|Inductance||Current Rating||Dimensions||DC Resistance||Part Number(1)|
|(ISAT at 25°C)||(L × W × H)|
|92 nH||24 A||4 × 4 × 1.2 mm||5.2 mΩ (typical)||Coilcraft, XEL4012-920NE|
|100 nH||30 A||4 × 4 × 3.2 mm||1.5 mΩ (typical)||Coilcraft, XEL4030-101ME|
|110 nH||29 A||4 × 4 × 2.1 mm||1.4 mΩ (typical)||Coilcraft, XGL4020-111ME|
|110 nH||29 A||3.2 × 2.5 × 2.5 mm||1.9 mΩ (typical)||TDK, CLT32-R11|
|55 nH||39.5 A||3.2 × 2.5 × 2.5 mm||1.0 mΩ (typical)||TDK, CLT32-55N|
|110 nH||17.0 A||3.2 × 2.5 × 2.5 mm||3.0 mΩ (typical)||Cyntec, VCTA32252E-R11MS6|
|100 nH||25 A||4.2 × 4.0 × 2.1 mm||1.9 mΩ (typical)||Cyntec, VCHA042A-R10MS62M|
|100 nH||44 A||5.45 × 5.25 × 2.8 mm||0.8 mΩ (typical)||Cyntec, VCHW053T-R10NMS5|