everything PE recently interviewed Neil LeJeune, Senior Director, Business Development at Littelfuse. Littelfuse specializes in circuit protection, power control, and sensing products.

Q1. Can you give us a brief history of Littelfuse? When was the company founded and what was the goal?

Neil LeJeune: Littelfuse was established in 1927 by Edward V. Sundt in Chicago, aiming to produce high-quality fuses for the automotive industry. Early success in this niche set the stage for expansion into broader markets. During the 1930s and 1940s, the company diversified its product line to include fuses for appliances and military applications during World War II, contributing significantly to its growth. Over the decades, it expanded its product range to include various circuit protection and semiconductor components. The company pursued growth through strategic acquisitions and diversification, entering new markets such as automotive and renewable energy.

Today, Littelfuse is a diversified industrial technology manufacturing company empowering a sustainable, connected, and safer world. We partner with customers across more than 20 countries and with approximately 16,000 global associates to design and deliver innovative, reliable solutions. Serving over 100,000 end customers, our products are found in a variety of industrial, transportation, and electronics end markets—everywhere, every day.

Q2. Can you tell us more about your product portfolio?

Neil LeJeune: Littelfuse offers a comprehensive product portfolio that addresses diverse needs across various industries. Our offerings include various circuit protection devices like fuses, protection relays, and temperature sensors. We also provide automotive electronics, power control devices, and sensors. These products ensure comprehensive solutions for safeguarding equipment and personnel from electrical faults, thereby minimizing downtime and reducing operational costs, which enhances overall system reliability and safety.

Regarding power solutions, Littelfuse stands out with its robust selection of power semiconductors. We offer components such as thyristors, rectifiers, and silicon carbide diodes, which are crucial for applications like motor control, power conversion, and renewable energy systems. Our power semiconductor portfolio supports milliwatt (mW) to megawatt (MW) applications, ensuring efficient and reliable performance across industrial, automotive, and consumer electronics sectors.

Q3. Which market segments do you cater to?

Neil LeJeune: Littelfuse serves diverse market segments with a comprehensive portfolio of semiconductor products designed to enhance safety, reliability, and performance. Our key market segments include:

•    Industrial Automation/drives/robotics

•    Medical imaging/X-RAY/MRI              

•    Power Supplies/Server Power/Specialty Power(plasma)

•    Power Quality/UPS/Solar Inverters

•    Induction Heating/Welding

•    Battery Charging and Storage

Littelfuse offers a wide range of products including fuses, circuit protection devices (like TVS diodes and ESD protection), relays, sensors (temperature, speed, and current), and power semiconductors (diodes, rectifiers, and thyristors), serving industries like automotive, industrial, electronics, and telecommunications.

Q4. What are the benefits of using Littelfuse wide band gap solutions in power systems?

Neil LeJeune: The Littelfuse wide band gap product portfolio prominently features Silicon Carbide (SiC) devices. These include discrete SiC MOSFETs and Schottky diodes with voltage ratings from 650 V to 1700 V, designed to offer superior efficiency, lower switching losses, and higher thermal conductivity compared to traditional silicon-based devices. SiC MOSFETs are available in various advanced packaging options, enhancing their performance and reliability in demanding applications such as electric vehicle charging stations, renewable energy systems, and industrial power supplies.

Advanced packaging solutions, like Surface Mount Power Device (SMPD) for Wide Bandgap (WBG) devices, enhance system manufacturability and minimize parasitic components in the package. In many cases, our advanced packaging solutions deliver exceptional thermal performance, which not only helps increase power density but also improves the overall lifespan of the device. Customers achieve higher efficiency and longer operational life from their WBG devices while benefiting from a more streamlined manufacturing process.

WBG Device

Q5. How do fuses contribute to the overall efficiency of EV battery packs? 

Neil LeJeune: Fuses play a crucial role in the overall efficiency and safety of electric vehicles (EVs) by providing the following contributions:

1. Protection of Electrical Components: Fuses protect sensitive and expensive electrical components from damage caused by overcurrent, possibly due to faults or short circuits. Quickly disconnecting the faulty circuit prevents further damage and reduces repair costs, maintaining the vehicle's operational efficiency.

2. Safety Enhancement: Ensuring the electrical system's safety is vital. Fuses help prevent potential electrical fires or failures that could lead to dangerous situations, thereby enhancing the reliability and safety of EVs.

3. System Longevity: By preventing damage to the electrical system, fuses contribute to the longevity of the vehicle's components. Doing so reduces the frequency of repairs and replacements, indirectly contributing to the vehicle's efficiency and cost-effectiveness over time.

4. Energy Efficiency: Fuses that function efficiently help minimize the energy loss caused by electrical faults. By quickly isolating problematic circuits, they help maintain the optimal performance of the electrical system, contributing to the overall energy efficiency of the vehicle.

Q6. What are the advantages of using SiC MOSFETs in high-voltage EV systems?

Neil LeJeune: While Littelfuse does not currently have any SiC MOSFETs products officially certified for automotive applications as per AEC qualification standards, the benefit of using Littelfuse SiC MOSFETs in SMPD or ISO-247 packages in high-voltage systems, including EV application is improved efficiency. SiC MOSFETs reduce conduction and switching losses compared to traditional silicon MOSFETs, which minimizes power dissipation and enhances overall system efficiency. This results in better energy utilization and can extend the vehicle's range, making the EV more efficient and effective in real-world driving conditions. 

The advanced packaging of SiC MOSFETs also supports higher power density in a compact footprint, which is crucial for the space-constrained environments of EV systems. This compact design allows more power to be handled in a smaller area, contributing to lighter and more space-efficient vehicle components. Additionally, SiC MOSFETs offer superior thermal performance, handling higher temperatures more effectively, which helps maintain device reliability and performance in the demanding thermal conditions of EV systems.

Beyond these efficiencies, SiC MOSFETs provide faster switching speeds, reducing the size and cost of passive components such as inductors and capacitors. This results in more compact and cost-effective designs. Their robustness and ability to operate at high voltages enhance reliability and support advanced power conversion stages. The ISO-247 package format ensures compatibility and efficient thermal management, facilitating integration into EV systems. Overall, Littelfuse SiC MOSFETs contribute to more efficient, reliable, and compact EV designs, enhancing performance and vehicle longevity.

Q7. Can you tell us about the battery energy storage components and solutions provided by Littelfuse that enhance the safety of battery-powered systems across various industries?

Neil LeJeune: Littelfuse offers a range of components and solutions designed to enhance the safety and reliability of battery-powered systems across industries like automotive, renewable energy, and industrial automation.

Essential components and solutions: 

1.    Fuses: Provide overcurrent protection in large-scale battery systems and electric vehicles, allowing for safer operation.

2.    Gate Drivers: Ensure efficient and reliable control of power switches like MOSFETs and IGBTs in battery management systems, improving overall system performance.

3.    TVS Diodes: Help protect battery management systems from voltage spikes, preventing damage to sensitive electronics.

4.    TVS Diode Arrays: Protects by clamping multiple lines in circuits, offering transient voltage suppression to help safeguard complex electronic systems.

5.    Circuit Protection: ESD suppressors and resettable PTCs help protect electronics from issues such as electrostatic discharge and overcurrent.

6.    Thermal Management: This section features products like TTape™ (Thermal Protection Tape) platform, thermistors, and temperature sensors that help manage thermal conditions and enhance safety in battery packs.

Q8. What are the key features of the Littelfuse Energy Storage Rack (ESR) fuse series? How does it enhance safety in stationary battery racks?

Neil LeJeune: The Littelfuse Energy Storage Rack (ESR) series of fuses is designed specifically to protect battery racks from a range of fault currents to avoid equipment damage or expensive system failures. The high-speed square body fuse is extremely fast-acting and responds quickly to safeguard battery racks or other devices in energy storage, power conversion, DC common bus systems, and hybrid PV-BESS (Battery Energy Storage System) inverters.

One of the standout features of the ESR fuses is their high interrupting rating, which ensures robust protection against overcurrent conditions. This rating is particularly critical in BESS environments where high fault currents can occur. The ESR range also features a low minimum breaking capacity; this allows battery rack OEMs to avoid using oversized DC contactors to achieve co-ordination and thanks to the compact design of the ESR range helps to save both space and cost in the BMS (Battery Management System)/BMU (Battery Management Unit) of battery racks. This compactness does not compromise their performance, allowing them to operate reliably under harsh conditions typical of BESS applications.

Additionally, these fuses have low power loss, which is essential for maintaining efficiency in BESS systems. This feature helps reduce energy wastage, thus contributing to the overall energy efficiency of the vehicle. 

The Class aBat partial range fuse has superior short circuit protection and a low minimum breaking capacity. It offers a reliable and broader range of DC over-current protection for battery-powered systems.

Q9. What are the key benefits of using Littelfuse surge protection devices in renewable energy systems? How are they different from other protection devices available in the market?

Neil LeJeune: Littelfuse SPDs (Surge Protection Devices) are designed to prevent damage from overvoltage in a system. Common transient overvoltage events are induced by the switching of the system loads, making it necessary to implement such devices to protect equipment, people, and other assets. The presence of surge protective devices within a system is more relevant now than ever with the continuing emergence of smaller and smaller electronic devices that are increasingly sensitive to overvoltage events. 

The Littelfuse SPD products can respond to surges in the nanosecond range, ensuring superior protection of systems and personnel while preventing costly downtime on critical function systems.

Q10. Can you tell us about the Littelfuse EV charging solutions?

Neil LeJeune: Littelfuse offers a comprehensive range of solutions tailored for electric vehicle (EV) charging systems, strongly emphasizing safety, reliability, and efficiency. 

Our product lineup is meticulously engineered to address various facets of EV charging infrastructure, including AC and DC charging stations and wireless charging stations. Below, you can see the solutions and components that Littelfuse offers for AC and DC charging stations. More information on the other EV applications can be found on our website.

AC Charging Station

DC Charging Station

Q11. Littelfuse has opened a new manufacturing plant in Piedras Negras, Coahuila, Mexico. How will this new plant impact Littelfuse global production capacity?

Neil LeJeune: Littelfuse opened a new manufacturing plant in Piedras Negras, Coahuila, Mexico on May 22nd, 2024. This new facility strengthens the Littelfuse commitment to customer satisfaction through innovative growth in the global industrial circuit protection sector. It highlights our commitment to sustainability and investment in our local communities.

 The newly opened and operational 106,000-square-foot facility, which doubles the current local Littelfuse manufacturing capacity while maintaining room for additional expansion, is located close to three other company operations in the city. The Littelfuse legacy and reputation as a leader in circuit protection are evident in this facility, which has already begun producing a wide range of electrical products for renewable energy, data centers and telecommunications, commercial construction, HVAC, and OEMs in factory automation and industrial machines.

Q12. What are the key goals Littelfuse has set for 2024? Is there an expansion in the company's product lineup?

Neil LeJeune: In early 2021, we launched a five-year growth strategy that targets double-digit sales growth, sustained profitability, and leveraged earnings expansion. This strategy continues into 2024, building on our structural growth themes of sustainability, connectivity, and safety. 

Organically, we are investing to support continued growth in customer-facing aspects of our business, manufacturing capacity, and productivity. We also focus on acquisitions to further strengthen our technologies and capabilities and diversify the end markets we serve. In early 2025, we anticipate closing on an acquisition of a 200 mm wafer fab located in Dortmund, Germany. This acquisition supports our long-term strategy by expanding our portfolio of technologies and growing internal capabilities, enabling Littelfuse to meet the increasing demands of our customers in high-growth power conversion operations.

About Neil LeJeune

Neil LeJeune is a Senior Director of Business Development at Littelfuse, Inc. His primary goals are to drive demand creation globally and provide a voice for the customer. He received his BSEE from the University of Pittsburgh and his EMBA from Katz Graduate School of Business. He has been with Littelfuse since they acquired IXYS in 2018 and has worked in the semiconductor industry for almost 36 years.