Power Inductor Selection for DC-DC Converters
Introduction to Power Inductor Selection
Power inductors are critical components in DC-DC converters. Proper selection requires understanding inductance requirements, current ratings, and core materials.
Inductance Calculation
the required inductance is calculated based on allowable ripple current. The formula considers input voltage, output voltage, switching frequency, and desired ripple.
Current Ratings
rated current is based on thermal limitations. Saturation current is the current at which inductance drops significantly. Both must be considered.
Core Material Selection
ferrite cores offer low losses at high frequencies. Metal composite cores provide soft saturation and higher saturation flux density.
Shielded vs Unshielded
Shielded inductors minimize EMI radiation. Unshielded inductors are smaller and lower cost but produce more EMI.
Conclusion
proper power inductor selection requires balancing multiple parameters. TDK's portfolio offers solutions for every application.
💡 FAE Insights
📋 Customer Cases
Telecom Equipment Manufacturer
Communications
Challenge
Inductor saturation causing instability in high-temperature equipment
Solution
Redesigned with metal composite inductors having better temperature characteristics
Customer Feedback
"Eliminated field issues with soft saturation characteristic"
Frequently Asked Questions
1. What is inductor saturation?
Saturation occurs when the core material reaches maximum flux density and inductance drops dramatically. This causes increased ripple current and potential converter instability. For detailed specifications and application support on tdk products, refer to the datasheet or contact our team.
2. How do ferrite and metal composite compare?
Ferrite offers low losses at high frequencies with sharp saturation. Metal composite provides soft saturation and higher flux density but higher losses. For detailed specifications and application support on tdk products, refer to the datasheet or contact our team.
3. What is the difference between rated and saturation current?
Rated current is thermal limitation. Saturation current is where inductance drops. In converters, saturation current is usually the limiting factor. For detailed specifications and application support on tdk products, refer to the datasheet or contact our team.
4. How does temperature affect inductors?
DCR increases with temperature. Saturation current decreases at high temperatures. Core losses may change with temperature. For detailed specifications and application support on tdk products, refer to the datasheet or contact our team.
5. Can inductors be paralleled?
Yes, but current sharing depends on inductance matching. Practical designs should use only 1.6-1.8x single inductor rating. For detailed specifications and application support on tdk products, refer to the datasheet or contact our team.