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BCL Series Power Inductors

The BCL series of automotive power inductors utilizes TDK’s proprietary material technology and structural design to achieve a wide range of inductance values while maintaining a compact size. By using metal magnetic materials, these inductors can handle higher currents compared to ferrite products and offer a broad operating temperature range, making them suitable for harsh automotive environments. <br>
This article provides an in-depth analysis of the BCL series' structure, features, and applications to assist in product selection.


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What is the BCL Series of Metal Power Inductors for Automotive Applications?

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Figure 1 provides an overview of the BCL series. The BCL series consists of two sub-series: the BCL3520FT, which uses flat (rectangular) wire to achieve low RDC (DC resistance) and low inductance, and the BCL322520RT, which uses thin wire to achieve high inductance values.

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SeriesBCL3520FTBCL322520RT
Product 
Overview

・ Wire-wound power inductor using metal magnetic material
・ Incorporates proprietary material and molding technologies

・ High efficiency in electrical circuits achieved through low RDC using flat wire
・ Low heat generation even under high current operation, suitable for high-density circuits

・ Wire-wound power inductor using metal magnetic material
・ Low-pressure molding achieved through proprietary material and molding technologies, resulting in reduced short-circuit risk
Reduced short-circuit risk allows the use of thinner wires, achieving high inductance
Supports higher current than ferrite inductors due to the use of metal magnetic material
Compact size enables high-density mounting

 

 

 

 

 

Inductors,Coils:BCL3520FT-D

BCL3520FT Appearance

     

      

Inductors,Coils:BCL322520RT

 

BCL322520RT Appearance

FeaturesOperating temperature range: -55°C to +155°C (including self-temperature rise)
Low leakage flux achieved through an integrated (fully molded) structure
High efficiency
Rated voltage: 40V
AEC-Q200 compliant
Low Inductance
(0.15~2.2μH)
High Inductance
(2.2~100μH)
Usage

Automotive Applications: ADAS, various ECUs 

tpl_application_icon02_ja.gif
Figure 1: What is the BCL Series Automotive Metal Power Inductor?
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Structure of the BCL Series: Utilizing Metal Magnetic Materials for a Wide Inductance Range

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The structure of the BCL series is illustrated in Figure 2. The BCL series consists of inductors manufactured using a wire-winding process. 
During fabrication, an air-core coil is molded with metal magnetic material, after which the wire leads extending from the bottom are connected to the terminals.

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Product_Structure
Figure 2: Product Structure
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Features of the BCL Series Achieved Through Proprietary Material Technology and Structural Design

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The BCL series uses metal magnetic materials with excellent DC bias (superimposition) characteristics, enabling it to handle higher current than ferrite inductors of the same size and shape.

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Comparison_of_DC_bias_characteristics

Inductance 10μH

Figure 3: Comparison of DC bias characteristics
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Furthermore, the BCL series achieves lower RDC compared with similar products from other manufacturers as well as TDK’s ferrite inductors of equivalent size. 
This reduces heat generation and power loss in high-current power supply circuits, thereby contributing to higher efficiency.

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Comparison_of_power_supply_efficiency

            [Measurement Conditions]
Switching Frequency Fsw=2.2MHz
                    Vin=12V, Vout=5.0V

Figure 4: Comparison of power supply efficiency
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Since the coil is a fully molded structure made of metal material, it results in low leakage flux. By using the BCL series, it is possible to achieve higher circuit efficiency, noise reduction, high current capability, and miniaturization.

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 TDK
BCL3520FT
(3.3x3.5x2.0mm)
Company A
Metal composite
(3.2x3.5x2.0mm)
TDK 
Ferrite Semi-Shield
(3.0x3.0x1.5mm)
TDK 
Ferrite Shield
(4.5x3.0x2.0mm)

Peak Level [dBuV]

BCL Similar Shape
Horizontal

Peak Level : 94.1 [dBuV]

Peak Level : 98.4 [dBuV]

Peak Level : 96.4 [dBuV]

Peak Level : 92.0 [dBuV]

Vertical

Peak Level : 99.1 [dBuV]

Peak Level : 104.6 [dBuV]

Peak Level : 99.9 [dBuV]

Peak Level : 94.3 [dBuV]

 [Measurement Conditions]
 Inductance 1.0μH
 Switching Frequency Fsw=2.2MHz
 Vin=12V、Vout=5.0V
 Iout=1.5A
 

Figure 5: Comparison of Leakage Flux
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Applications of the BCL Series

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Figure 6 shows application examples of the BCL series. With a guaranteed voltage rating of 40V, the BCL series can be used for input filters of 12V power supplies and DC/DC converters.
Within the 3mm square size, a wide lineup of inductance values is available, allowing selection of the optimal product based on switching frequency, inductance, and current requirements.

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Applications
Figure 6: Applications
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BCL Series Lineup List

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Click the links below to view detailed information on the BCL series or to request samples. By further expanding our lineup, we will continue to meet our customers' diverse needs for power circuit inductors.

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SeriesApplicationL Dimension
±0.2mm
W Dimension
±0.2mm
T Dimension 
max.
Inductance (μH)
±20%
DC Resistance (Ω) 
Typ.
Rated Current
Isat(A) Typ.
BCL3520FT
tpl_application_icon02_ja.gif

Automotive Grade

3.33.52.00.15~2.20.0027~0.0214.5~15.9
BCL322520RT3.22.52.02.2~1000.055~1.990.70~4.31
 Figure 7: Product Details
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What Are Power Inductors?

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Power inductors are inductors used for power supply circuit such as DC-DC converters. They are also called power coils or power choke coil. One of the inductors' characteristics is that they store energy by self-induction function. Chopper type DC-DC converters use inductors having such characteristics with switching devices for voltage conversion (see Figure 8).
Depending on the processing method, inductors can be classified into multilayer type, thin-film type, and wire-wound type. Since wire-wound type permits large current to flow, most of the power inductors are wire-wound type. Various wound-type power inductor products with ferrite or soft magnetic metal core are offered. Recently, the multilayer type and thin-film type, with which reduction of size and thickness can be achieved, are being improved to allow for larger current.

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DC-DC_converter_(chopper_type_/_step-down_type)_and_inductor
Figure 8: DC-DC converter (chopper type / step-down type) and inductor
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Contact Us

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Contact

Please click here for information on the list of distributors.

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