SNVSCC4 October 2023 LP5811
PRODUCTION DATA
The inductor is the most important component in power regulator design, which affects steady-state operation, transient behavior, and loop stability. There are three important inductor specifications, inductor value, saturation current, and dc resistance (DCR).
The integrated boost converter in LP5811 is designed to work with inductor values between 0.37 µH and 2.9 µH. 1 µH is recommended in typical application. The inductor peak current can be calculated by Equation 8. Using the minimum input voltage, maximum output voltage, and maximum load current of the application can calculate the worst case.
In a boost regulator, the inductor dc current can be calculated by Equation 6.
where
The inductor ripple current is calculated by Equation 7.
where
Therefore, the inductor peak current is calculated by Equation 8.
Inductor peak-to-peak current is recommended to be designed less than 40% of the average inductor current, with maximum output current setting. Large inductor value reduces the magnetic hysteresis losses in the inductor and improves EMI performance with small inductor ripple, but the load transient response time increases. The saturation current of the inductor must be higher than the calculated peak inductor current.
Part Number | L (µH) | DCR MAX (mΩ) | SATURATION CURRENT (A) | SIZE L×W×H (mm) | VENDOR |
---|---|---|---|---|---|
XEL4030-102ME | 1 | 9.78 | 9.0 | 4.0 × 4.0 × 3.1 | Coilcraft |
74438357010 | 1 | 13.5 | 9.6 | 4.1 × 4.1 × 3.1 | Wurth Elecktronik |
HBME042A-1R0MS-99 | 1 | 11.5 | 7.0 | 4.1 × 4.1 × 2.1 | Cyntec |