With the rapid advancement of fast-charging technology, consumer demands for charger power density, efficiency, and stability are increasingly high. As critical components in electronic circuits, the selection and design of inductors directly impact the overall performance of the charger.
Recently, we disassembled a commercially available 45W fast charger and found that it skillfully incorporates various magnetic components, including Color Ring Inductors and Drum Core Inductor, working together to build an efficient and stable power conversion system.
After disassembling the shell and cleaning the white glue, the front of the board is equipped with delay fuses, Drum core inductor, high-voltage filtering electrolytic capacitors, transformers, and other devices.
In today’s rapidly evolving fast-charging landscape, consumers expect faster, safer, and more efficient charging experiences. The 45W power level has become mainstream, sufficient to meet the fast-charging needs of smartphones, tablets, and other mobile devices.
High power density design results in compact internal layouts in modern chargers, making the selection of each component critical.
As core components for electromagnetic energy conversion, inductors perform key tasks such as filtering, energy storage, and power transfer within chargers, directly impacting the circuit’s conversion efficiency, thermal performance, and output stability.
Disassembling this 45W fast charger reveals a highly integrated power management solution. Public information indicates that a typical 45W fast charging solution generally consists of three core parts: AC-DC conversion, synchronous rectification, and protocol identification.
This solution uses the PN8783 as the main control chip, which integrates a current-mode controller, a high-voltage startup module, and a high-performance GaNFET, specifically designed for high-performance fast-charging switch-mode power supplies.
The secondary side employs the PN8307P synchronous rectification chip, which includes a synchronous rectification controller and a built-in high avalanche capability power MOSFET, replacing traditional secondary rectifier Schottky diodes.
The protocol identification section uses a highly integrated fast-charging protocol chip supporting various fast-charging protocols, including BC1.2, QC2.0/3.0, SCP, AFC, PD2.0/3.1, PPS, and Apple 5V2.4A.
In this precise system, Color Ring Inductors and Drum core inductor each play distinct and vital roles.
Drum core inductor Inductors are a type of plug-in electronic component with an “I”-shaped structure, composed of high-frequency choke coils and low-frequency choke coils. In this 45W fast charger, I-Core Inductors primarily handle high-current tasks.
In power circuits, the rectifier circuit converts AC to pulsating DC. A large-capacity Color Ring Inductor is often connected after the rectifier circuit. Using its charge-discharge characteristics, it smoothes the rectified pulsating DC voltage into a relatively stable DC voltage.
Color Ring Inductors in parallel with capacitors can form LC tuning circuits. When the natural resonant frequency of the circuit matches the frequency of an AC signal, the inductive reactance and capacitive reactance of the circuit become equal, causing electromagnetic energy to oscillate back and forth between the inductor and capacitor.
When engineers design chargers, they carefully deliberate over the selection of every component. Whether it’s the efficient performance of I-Core Inductors in power conversion or the stable operation of Color Ring Inductors in circuit protection, they collectively form the foundation for the steady progress of fast-charging technology.
In the future, with continuous breakthroughs in semiconductor technology and magnetic materials, this traditional component—the inductor—will continue to evolve, achieving higher efficiency and power density in smaller volumes, providing a solid guarantee for the next generation of charging technology.
We are a professional inductor manufacturer. If you have any inductor requirements or need samples for your fast-charging projects, please feel free to contact us for quotations and samples.
Email: wayne@hunstle.com