FAQ
The standard industry solution for this power level is to use interleaving PFC stages, or stepping up to a 3-phase PFC topology. It means the circuit needs 2 PFC chokes for interleaving topology or 3 PFC chokes for 3-phase PFC topology, not single phase PFC topology.
ITG have some thermal solution with utilizing a high-thermal-conductivity thermal glue to bridge the gap between the PFC choke with ITG thermal jacket. This method will keep same foot print with very similar dimension.
When PFC choke, we have to decide the topology at first. The topology will affect the parameters of PFC choke. Inductance when load, Isat, and DCR are key electrical parameters.
Yes, ITG have some thermal solution with utilizing a high-thermal-conductivity thermal glue to bridge the gap between the PFC choke with ITG thermal jacket. This pulls the heat out of PFC choke efficiently.
Absolutely! ITG is continuously dedicated to developing innovative solutions and expanding our molded inductor portfolio. For a performance upgrade, we highly recommend our SMF series (featuring flat wire technology), which significantly optimizes DCR, enhances Isat, and improves overall efficiency. Please feel free to contact the ITG sales team or visit our website to request samples or obtain technical support.
Yes, you can absolutely use a 200 kHz-tested inductor for your 125 kHz application.
When 125kHz application, the AC Resistance will drop, core losses will be lower and inductance will remain stable.
We generally do not recommend using molded inductors in applications with very high step-up/down voltage ratios, as they have relatively lower rated voltages compared to assembly inductors. Molded inductors are composed of high-density metal powders, where insulation relies entirely on a thin coating layer over each particle. During the high-tonnage compaction process, this coating layer can be slightly compromised, reducing the insulation resistance between the powder particles. When a high voltage is applied, this lower insulation resistance may lead to increased leakage current. Therefore, for designs requiring high voltage conversion ratios, we highly recommend considering assembly inductors instead.
Resonant inductors with a 10% tolerance is a low-cost solution.
Resonant inductors with a 5% tolerance are the ideal solution for fixed-frequency resonant converters, LLC converters with a narrow frequency control range, interleaved resonant converters, and applications with strict requirements regarding efficiency and thermal budgets.
Assembly Inductors: Typically offer lower DCR, lower core loss, and higher rated voltage.
This makes them exceptionally well-suited for high-current and high step-up/down ratio applications, such as core power supplies for CPUs, GPUs, and ASICs.
Molded Inductors: Feature highly flexible dimensions and better cost-efficiency. They are ideal for applications with severe space constraints, lower step-up/down ratios, or peripheral power rails (side rails) with moderate Isat requirements.
RL130815 series code A indicates high accuracy (5% tolerance) of inductance, code B indicates 10% tolerance of inductance.
The main advantages of molded inductors include compact size, low EMI, and soft saturation performance. Consequently, they are highly suitable for applications with strict space limitations, stringent EMI requirements, or potential risks of sudden inductance collapse.
Resonant inductors (like those used in LLC or phase-shift converters) operate under unique conditions that make ACR the primary limiting factor for efficiency.
By explicitly publishing the ACR on the datasheet, ITG is letting you know exactly how well their winding arrangement (whether flat wire, specialized positioning, or partial Litz) has managed to mitigate that severe fringing field penalty at high frequency.
Isat (Saturation Current): Defines the amount of DC current that causes the inductance to drop by a specified percentage (typically 20% or 30%) due to magnetic saturation.
Irms (RMS Current): Focuses on the temperature rise of the inductor body, representing the continuous DC current that causes the component's temperature to increase by a specified increment (typically △T=40℃).
It depends on the PFC topology, operating frequency, targeted efficiency, dimension, cost, and so on.
The primary advantage of the magnetic powder is its soft saturation characteristic.
Soft saturation means that as the DC current increases, the inductance drops gradually rather than dropping abruptly.
This prevents a sudden collapse of inductance, thereby protecting the circuit from current spikes.
The core differences between assembly and molded inductors lie in their manufacturing processes and physical structures.
- Assembly Inductors: Manufactured by assembling
coils with pre-formed magnetic cores, resulting in a structure with
distinct air gaps. - Molded Inductors: Constructed by placing
pre-wound coils into a mold, filling it with magnetic powder (typically
iron or alloy powder), and applying tonnage-level pressure to form a gapless
structure.
Due to this gapless design, molded inductors effectively minimize EMI and acoustic noise. Furthermore, the molding process allows for smaller, lower-profile form factors, making them ideal for space-constrained and cost-sensitive applications.