ZHCSI15L June 2006 – May 2018 TPS65023 , TPS65023B
PRODUCTION DATA.
Each of the converters in the TPS65023x typically use a 2.2-μH output inductor. Larger or smaller inductor values are used to optimize the performance of the device for specific operation conditions. The selected inductor has to be rated for its DC resistance and saturation current. The DC resistance of the inductance influences directly the efficiency of the converter. Therefore, an inductor with lowest DC resistance must be selected for highest efficiency.
For a fast transient response, a 2.2-μH inductor in combination with a 22-μF output capacitor is recommended.
Equation 8 calculates the maximum inductor current under static load conditions. The saturation current of the inductor must be rated higher than the maximum inductor current as calculated with Equation 8. This is needed because during heavy load transient the inductor current rises above the calculated value.
where
The highest inductor current occurs at maximum Vin.
Open-core inductors have a soft saturation characteristic, and they can usually handle higher inductor currents versus a comparable shielded inductor.
A conservative approach is to select the inductor current rating just for the maximum switch current of the TPS65023x (2 A for the VDCDC1 and VDCDC2 converters, and 1.5 A for the VDCDC3 converter). The core material from inductor to inductor differs and has an impact on the efficiency especially at high switching frequencies.
See Table 18 and the typical applications for possible inductors.
DEVICE | INDUCTOR VALUE | TYPE | COMPONENT SUPPLIER |
---|---|---|---|
All converters | 2.2 μH | LPS4012-222LMB | Coilcraft |
2.2 μH | VLCF4020T-2R2N1R7 | TDK | |
For DCDC2 or DCDC3 | 2.2 uH | LQH32PN2R2NN0 | Murata |
For DCDC1 | 1.5 uH | LQH32PN1R5NN0 | Murata |
All converters | 2.2 uH | PST25201B-2R2MS | Cyntec |