FAQ
PFC电感的作用包括:塑形输入电流以跟随交流市电电压(改善功率因数)、存储并传递能量以调节输出直流电压、抑制输入浪涌电流、作为纹波电流滤波器以及EMI滤波器。
LLC谐振槽路由两个元件组成,即Lr和Cr。
串联谐振频率 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提供一种散热解决方案,利用高导热系数的导热胶,填补PFC电感与ITG散热外套(thermal jacket)之间的间隙。该方法可在几乎相同的占位面积与尺寸下实现散热改善。
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提供一种散热解决方案,利用高导热系数的导热胶,填补PFC电感与ITG散热外套(thermal jacket)之间的间隙,从而高效地将热量从PFC电感中导出。
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,您完全可以将在200kHz下测试的电感用于125kHz的应用。
在125kHz应用条件下,交流电阻会降低,磁芯损耗也会更低,而电感值将保持稳定。
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%公差的谐振电感是一种低成本方案。
5%公差的谐振电感则是固定频率谐振变换器、频率控制范围较窄的LLC变换器、交错式谐振变换器,以及对效率和热设计裕量要求严格的应用场景的理想选择。
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,代码A表示电感值具有高精度(5%公差),代码B表示电感值公差为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.
谐振电感(如用于LLC或移相变换器的电感)工作在特殊条件下,使得ACR成为限制效率的主要因素。
通过在数据手册中明确标注ACR,ITG可以让您准确了解其绕组结构(无论是采用扁平线、特殊绕线布局,还是部分利兹线)在缓解高频边缘磁场(fringing field)所带来的严重损耗方面究竟表现如何。
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℃).
这取决于PFC拓扑结构、工作频率、目标效率、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.