ZHCSBD3D July 2013 – August 2019 TPS63050 , TPS63051
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Device Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Detailed Description
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
9.2.2.3 Inductor Selection
The inductor selection is affected by several parameter like inductor ripple current, output voltage ripple, transition point into power save mode, and efficiency. See Table 5 for typical inductors.
Table 5. List of Recommended Inductors
| INDUCTOR VALUE | COMPONENT SUPPLIER(1) | SIZE (L × W × H mm) | Isat / DCR |
|---|---|---|---|
| 1 µH | TOKO 1286AS-H-1R0M | 2 × 1.6 × 1.2 | 2.1 A / 68 mΩ |
| 1.5 µH | TOKO, 1286AS-H-1R5M | 2 × 1.6 × 1.2 | 2.5 A / 95 mΩ |
| 1.5 µH | TOKO, 1269AS-H-1R5M | 2.5 × 2 × 1 | 2.1 A / 90 mΩ |
| 2.2 µH | TOKO 1286AS-H-2R2M | 2 × 1.6 × 1.2 | 2 A / 160 mΩ |
For high efficiencies, the inductor must have a low dc resistance to minimize conduction losses. Especially at high-switching frequencies, the core material has a high impact on efficiency. When using small chip inductors, the efficiency is reduced mainly due to higher inductor core losses. This needs to be considered when selecting the appropriate inductor. The inductor value determines the inductor ripple current. The larger the inductor value, the smaller the inductor ripple current and the lower the conduction losses of the converter. Conversely, larger inductor values cause a slower load transient response. To avoid saturation of the inductor, the peak current for the inductor in steady state operation is calculated using Equation 6. Only the equation which defines the switch current in boost mode is shown, because this provides the highest value of current and represents the critical current value for selecting inductor.
where
- D = Duty Cycle in Boost mode
where
- η = Estimated converter efficiency (use the number from the efficiency curves or 0.80 as an assumption)
f = Converter switching frequency (typical 2.5MHz)
L = Inductor value
NOTE
The calculation must be done for the minimum input voltage that is possible to have in boost mode.
Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation current of the inductor needed. It's recommended to choose an inductor with a saturation current 20% higher than the value calculated using Equation 6. Possible inductors are listed in Table 5.