FAQ
PFC電感的作用包括:塑形輸入電流以跟隨交流市電電壓(改善功率因數)、儲存並傳遞能量以調節輸出直流電壓、抑制輸入突波電流,以及作為漣波電流濾波器與EMI濾波器。
LLC諧振槽路由兩個元件組成,即Lr與Cr。
串聯諧振頻率 fr = 1/2π√(Lr*Cr) → Lr = 1/((2πfr)²*Cr)
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提供一種散熱解決方案,利用高導熱係數的導熱膠,填補PFC電感與ITG散熱外套(thermal jacket)之間的間隙。此方法可在幾乎相同的佔位面積與尺寸下實現散熱改善。
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.
可以,ITG提供一種散熱解決方案,利用高導熱係數的導熱膠,填補PFC電感與ITG散熱外套(thermal jacket)之間的間隙,藉此高效地將熱量從PFC電感導出。
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.
可以,您完全可以將在200kHz下測試的電感用於125kHz的應用。
在125kHz應用條件下,交流電阻會降低,磁芯損耗也會更低,而電感值將維持穩定。
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.
10%公差的諧振電感是一種低成本方案。
5%公差的諧振電感則是固定頻率諧振變換器、頻率控制範圍較窄的LLC變換器、交錯式諧振變換器,以及對效率與熱設計裕度要求嚴格的應用場景的理想選擇。
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.
在RL130815系列中,代碼A表示電感值具高精度(5%公差),代碼B表示電感值公差為10%。
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.
諧振電感(如用於LLC或移相變換器的電感)運作於特殊條件下,使得ACR成為限制效率的主要因素。
透過在數據表中明確標示ACR,ITG可讓您準確了解其繞組結構(無論是採用扁平線、特殊繞線佈局,或部分利茲線)在緩解高頻邊緣磁場(fringing field)所帶來的嚴重損耗方面究竟表現如何。
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℃).
這取決於PFC拓撲結構、工作頻率、目標效率、尺寸、成本等多方面因素。
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.