Product Overview Power Inductor SPM Series
The SPM series power inductors are the metal composite type wire-wound inductors that have the coils integrally molded with metallic magnetic powder. Compared to ferrite-base wire-wound inductors, the SPM series inductors realize larger current, lower Rdc, smaller size and superior DC bias characteristic. In addition, they ensure low magnetic flux leakage and are effective as a means to suppress acoustic noise of the coil. This article introduces the structure, features, and application of these products, and other information that helps you in an easy-to-understand way.Table of contents
Product summary
The SPM series are the inductors that have the coils integrally molded with metallic magnetic powder. TDK offers a large selection of the SPM series inductors, including the low-profile SPM-LR series, the SPM-HZ series for automotive applications, etc.
Series | ||||||
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Product summary | Metal composite type inductorThe inductors that have the coils integrally molded with magnetic powder.These inductors use Fe-base alloy powder to have high saturation characteristics, i.e. allowing for large current. The inductors of this series are offered in large selection of product sizes. |
Metal composite type low-profile inductorThe inductors that have the coils integrally molded with magnetic powder.These inductors use Fe-base alloy powder to have high saturation characteristics, i.e. allowing for large current. The low-profile (H = 1.0 to 2.0 mm) is achieved by employing the terminal of proprietary shape. |
Metal composite type large inductorThe inductors that have the coils integrally molded with magnetic powder.These inductors use Fe-base alloy powder to have high saturation characteristics, i.e. allowing for large current. A simple structure without exterior terminals is achieved by employing the wire collinear electrode structure. |
Metal composite type inductor for high frequency applicationsThe inductors that have the coils integrally molded with magnetic powder.By using the proprietary alloy powder, low loss in the high frequency region is achieved, in addition to having high saturation characteristics. |
Metal composite type inductor for automotive applicationsThe inductors that have the coils integrally molded with magnetic powder.These inductors use Fe-base alloy powder to have high saturation characteristics, i.e. allowing for large current. The inductors of this series are designed for automotive applications. |
Metal composite type inductor for automotive applicationsThe inductors that have the coils integrally molded with magnetic powder.These inductors use Fe-base alloy powder to have high saturation characteristics, i.e. allowing for large current. Compared to the SPM-HZ series, this series inductors have wider operating temperature range in automotive environments. |
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Product structures
Figure 2 shows the structure of each SPM series. The integral mold structure and the welding method for connecting the wire and terminals achieves high reliability.
Series | SPM series | SPM-LR series | SPM-XT series | SPM-CT series | SPM-HZ series | SPM-VT series |
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Product features
Figure 3 shows the features of each SPM series.
Series | SPM series | SPM-LR series | SPM-XT series | SPM-CT series | SPM-HZ series | SPM-VT series |
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Appearance | ||||||
Operating temperature range | -40 to 125°C (including self-temperature rise) |
-55 to 155°C (including self-temperature rise) |
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Magnetic material | Metallic magnetic material | |||||
Terminal electrode specifications | Metal terminal + plating | Wire collinear electrode + plating | Metal terminal + plating | |||
Features | Standard specifications | Low-profile specifications | Large current specifications | High frequency & High Q specifications | Automotive application specifications |
One of the remarkable features of the SPM series is that they are made with metallic magnetic core. Compared to ferrite cores, metallic magnetic cores have higher magnetic saturation density and better DC bias characteristic. In addition, since their Curie temperature is high, they show only a small change in characteristics with ambient temperature.
Core material characteristics of high magnetic saturation
Superior DC bias characteristic
Core material characteristics of high Curie temperature
Change in characteristics with ambient temperature is small.
Since the SPM series inductors are made with wire-wound cores integrally molded with metallic magnetic powder, they do not have a core gap and the acoustic noise is reduced. Also, they have good shielding qualities and the magnetic flux leakage is small.
Core gapless (integral molding) for suppressing acoustic noise
Contributes to improve the set quality
Shielding structure for low magnetic flux leakage
Effective for reducing EMI
Vertical near magnetic field measurement result
List of products
Figure 8 shows the list of products by series and by shape. You can view the detailed information of the product or purchase a sample by clicking the type name.
- Commercial grade
- Automotive grade
Size (mm) |
SPM series | SPM-LR series | SPM-XT series | SPM-CT series | SPM-HZ series | SPM-VT series |
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3mm sqr. | 3.2x3.0mm SPM3010-LR SPM3012-LR SPM3015-LR SPM3020-LR |
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4mm sqr. | SPM4030 |
4.2x4.0mmSPM4010-LR SPM4012-LR SPM4015-LR SPM4020-LR |
4.4x4.1mmSPM4030-HZ |
4.2x4.0mm|||
5mm sqr. | SPM5030 |
5.2x5.0mmSPM5010-LR SPM5012-LR SPM5015-LR SPM5020-LR |
5.4x5.1mmSPM5030-HZ |
5.2x5.0mm|||
6mm sqr. | SPM6530 SPM6550 |
7.1x6.5mmSPM6550CT |
7.1x6.5mmSPM6530-HZ SPM6550-HZ |
7.1x6.5mm|||
7mm sqr. | SPM7054VT |
7.5x7.0mm|||||
10mm sqr. | SPM10040 |
10.7x10.0mmSPM10040XT |
11.5x10.0mmSPM10040-HZ SPM10054-HZ |
10.7x10.0mmSPM10065VT |
10.5x10.0mm||
12mm sqr. | SPM12565XT |
12.6x13.0mmSPM12565VT |
13.0x12.5mm
What are power inductors?
Power inductors are inductors used for power supply circuit such as DC-DC converters. They are also called power coils or power chalks. 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 9).
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.
The voltage is dropped to a desired level in accordance with the duty ratio (the ratio that indicates how long the switch is ON during the switching cycle) setting.
Switching
repeated
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Inductor (coil) product information
Various information on TDK Group's inductors (coils) are comprehensively provided on this page.
- Lineup
- Inductors for high frequency applications Selection Guide
- Inductors for Power Circuits Selection Guide (Commercial Grade)
- Inductors for Power Circuits Selection Guide (Automotive Grade)
- Inductors for standard circuits/decoupling circuits Selection Guide
- Application Note "Selection Guide for Power Inductors in Consideration of Leakage Flux"
- Solution Guide "Solutions for silencing DC-DC converters - Measures Against Acoustic Noise in Power Inductors"