What is the power of Vishay IHLE® electric field shielded power INDUCTORS? A next-generation solution that combines EMI countermeasures with space-saving designs

Vishay Intertechnology, Inc.

How do you choose the "last line of defense" for EMI prevention?

In electronic devices equipped with SWITCHING POWER SUPPLIES or microcomputers, noise caused by EMI (Electromagnetic Interference) can interfere with peripheral circuits and communication devices, risking malfunction and communication failure. For this reason, EMI countermeasures are an important consideration from the early stages of product design.
In particular, automotive and industrial equipment must comply with strict EMC (Electromagnetic Compatibility) standards, requiring high levels of noise limits such as CISPR25 Class 5. This often requires the addition of metal shielding as a noise countermeasure or complex board layouts to ensure distance from noise sources, significantly impacting design freedom and costs.
Vishay's IHLE® series is gaining attention as a new approach to solving these design challenges in EMI countermeasures. In addition to conventional magnetic field (B field) countermeasures, the IHLE integrates a dedicated shield into INDUCTORS body that suppresses the electric field (E field), a component of electrostatic noise. This revolutionary structure enables EMI countermeasures to be achieved without the use of an external metal shield.
This column provides hints for selecting products for EMI countermeasures by explaining the structure and noise reduction effect of the IHLE series, application examples, and comparing it with other products. This provides information that is directly relevant to the practical work of development engineers who are facing challenges in EMC design.

Technical explanation | Structure and effects of IHLE integrated with electric field shield

Generation and effects of electromagnetic fields

Whenever current flows through an electronic circuit, two types of electromagnetic fields are generated: a magnetic field (B field) and an electric field (E field), which radiate at right angles to each other and can affect surrounding electronic components.
Magnetic fields are an essential element for the operation of motors and TRANSFORMERS, but if they are not properly controlled, they can generate unnecessary voltages in surrounding wiring and components, causing noise.On the other hand, electric fields play an important role as the basic principles of static electricity and wireless communications, but if they are not properly controlled within electronic circuits, they can interfere with surrounding circuits and communication devices as unnecessary radiated noise, causing EMI.

IHLE Innovation: Integrated E-Field Shielding

Conventionally, the most common way to suppress magnetic field leakage has been to use "shielded INDUCTORS" that encase the entire coil in magnetic material. Vishay's IHLP® series is a representative example of this, which uses a molded structure that encases the entire coil in magnetic resin, significantly suppressing B field leakage.
However, while structures like IHLP are effective at suppressing magnetic fields, they are unable to sufficiently suppress the radiation of electric fields, making it necessary to provide a separate metal shield on the board. Such additional measures raise new issues, such as an increase in the number of components, an expansion of the mounting area, and even higher costs.
The IHLE series uses a structure in which a copper electric field shield is integrated on top of the IHLP INDUCTORS, which provides a high level of noise suppression, reducing E-field radiation by up to 20 dB. This shield is surface-treated with nickel and tin, and is effective when connected to the ground on the board.
This structure increases INDUCTORS height by just 0.3 mm while maintaining the same INDUCTORS, rated current, and direct current resistance (DCR) as the IHLP series, allowing for smooth replacement of existing designs.

Actual measurement data shows noise reduction effect

According to Vishay's internal evaluation, when comparing INDUCTORS of the same size and INDUCTORS in a DC/DC converter circuit, the IHLE demonstrated the lowest radiated noise compared to FERRITES core INDUCTORS and the IHLP.
The induced voltage measured with a detection coil placed 1 cm away was approximately 3.4 mV for FERRITES core INDUCTORS, 1.0 mV for the IHLP, and just 0.28 mV for the IHLE, quantitatively confirming the significant reduction in the E field.

Application circuit examples | Design scenes where IHLE can be utilized

・Automotive DC/DC converters

In automotive applications that require compliance with strict EMC standards such as CISPR25 Class 5, the IHLE's E-field suppression performance of up to 20 dB significantly contributes to reducing radiated noise and simplifying designs by eliminating the need for external shielding, thereby reducing the mounting area on the board, the number of components, and leading to cost savings.

・ LED DRIVER circuit

According to Vishay's evaluation, when the IHLE4040DD was compared with other manufacturers' INDUCTORS on an LED DRIVER evaluation board, the IHLE recorded radiated noise that was more than 10 dB lower under measurement conditions of CISPR25 Class 5. For LED lighting and DISPLAY drive circuits, where noise countermeasures are important, the IHLE is an effective choice that exhibits high EMI suppression effects.

・Industrial POWER SUPPLIES modules

IHLE maintains stable electrical performance even in high-current, high-frequency operating environments such as POWER SUPPLIES and industrial POWER SUPPLIES, and effectively suppresses noise interference in surrounding circuits. This reduces the design man-hours and number of prototypes required for EMI countermeasures, leading to shorter development times and faster time to market.

・High frequency digital measuring instrument

High-frequency digital measuring instruments such as oscilloscopes and spectrum analyzers must minimize the effects of external noise to accurately measure minute signals. The IHLE can effectively suppress both B and E fields, helping to ensure measurement accuracy and minimize noise within the enclosure. The IHLE's integrated structure is particularly advantageous for noise suppression in small enclosures with limited shielding space.

Product lineup | Sizes and specifications

The IHLE series is currently in mass production in the 4040 size (10 x 10 x 4.3 mm), and is planned to be expanded to include sizes equivalent to those of the IHLP series, such as 5050 (13 x 13 mm), 3232 (8 x 8 mm), 2525 (6.5 x 6.5 mm), 2020 (5 x 5 mm), and 1616 (4 x 4 mm).
Each size has the same INDUCTORS value, rated current, and DC resistance (DCR) as the IHLP series, making it easy to replace existing designs. This allows for improved EMI countermeasures while maintaining design flexibility.

External photo
Dimensions and height

package size	Series Name	Vishay Official Link
2020	IHLE-2020CD-5A	https://www.vishay.com/en/product/34577/
2525	IHLE‑2525CD‑5A	https://www.vishay.com/en/product/34388/
3232	IHLE-3232DD-5A	https://www.vishay.com/en/product/34378/
4040	IHLE-4040DD-5A	https://www.vishay.com/en/product/34380/
5050	IHLE-5050FH-5A	https://www.vishay.com/en/product/34459/

Representative series name by package size

Comparison with other products | IHLE vs IHLP vs FERRITES INDUCTORS

The comparison table below summarizes the main characteristics of common FERRITES INDUCTORS, Vishay's IHLP series, and the IHLE series. It clearly shows the superiority of the IHLE in terms of EMI countermeasures and ease of mounting.

Characteristics	FERRITES (open magnetic circuit)	IHLP (closed magnetic path)	IHLE (closed magnetic circuit + E-shield)
B-field suppression	△ (large leakage)	◎ (almost contained)	◎ (equivalent to IHLP)
E-field suppression	×	△	◎ (maximum 20dB reduction)
The need for an external shield	need	Required depending on conditions	Basically unnecessary
Mounting Height	standard	standard	+0.3mm (IHLP ratio)
Mechanical strength (vibration resistance)	△ (2 TERMINALS)	〇	◎ (4 TERMINALS structure)

Summary | IHLE, the new standard in EMI countermeasures, brings design freedom

EMI countermeasures are an important design element that not only ensures product reliability, but also has a significant impact on board design freedom, component costs, product size, and even development speed.
Vishay's IHLE series reduces the E field, the main cause of EMI, by up to 20 dB by integrating an electric field shield into INDUCTORS body. This innovative solution enables noise suppression without relying on conventional external shielding. Eliminating the need for an external shield reduces the number of components and makes effective use of board area, simplifying the design and reducing costs.
The IHLE series inherits the high reliability and electrical performance of the IHLP while enhancing its electric field noise suppression function, making it the ideal power INDUCTORS for today's high-density packaging that requires EMI countermeasures.
IHLE is an extremely effective solution that simultaneously improves design reliability and efficiency in applications with strict noise requirements, such as automotive equipment, industrial POWER SUPPLIES, and LED lighting.

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