Littelfuse L25S012 - Designed to protect today’s equipment and systems, Littelfuse semiconductor fuses are manufactured with Littelfuse-developed technology that sets tomorrow’s standards for accuracy, consistent quality, reliability, and predictable performance. By using advanced metallurgical, polymer, and materials research; mathematical modeling, and computerized statistical analysis; Littelfuse engineers have redefined “State-of-the-Art.”
Littelfuse

L25S012

Alternate Item Number: L25S012.T

UPC: 079458840124

Documents & Media
BrochureTechnical BulletinTechnical DrawingSpecification SheetVideo Clip

Contact for Pricing

Overview

The Littelfuse L25S012 semiconductor fuse represents the pinnacle of protection technology for modern industrial, commercial, and power electronics systems. Engineered by Littelfuse—a global leader in circuit protection solutions—the L25S012 combines cutting-edge metallurgical research, advanced polymer science, and precision manufacturing to deliver unparalleled performance in critical applications. This semiconductor fuse is specifically designed to safeguard sensitive electronic components from overcurrent conditions, voltage spikes, and short circuits, ensuring operational integrity and extending equipment lifespan in demanding environments. Semiconductor fuses like the L25S012 are essential in applications where precision protection is non-negotiable. Unlike conventional fuses, semiconductor fuses are engineered for ultra-fast response times, low let-through energy (I²t), and high interrupting ratings, making them ideal for protecting power semiconductors, IGBTs, thyristors, and other high-performance components. The L25S012 leverages Littelfuse’s proprietary technology, including advanced mathematical modeling and computerized statistical analysis, to achieve consistent breaking capacity and predictable performance across a wide range of fault conditions. This ensures that even in the most transient or high-energy fault scenarios, the fuse operates reliably without compromising system safety or component integrity. Typical applications for the Littelfuse L25S012 include power conversion systems, motor drives, renewable energy inverters, industrial automation, and high-frequency switching power supplies. In solar photovoltaic (PV) installations, for example, semiconductor fuses protect inverters from reverse current and overcurrent events, preventing damage to sensitive power electronics. Similarly, in electric vehicle (EV) charging infrastructure, these fuses ensure safe operation under high-current conditions, complying with stringent safety standards such as UL 248 and IEC 60269. The L25S012’s robust design also makes it suitable for use in railway traction systems, medical equipment, and aerospace applications, where reliability and fault tolerance are paramount. Installation and selection of the L25S012 should be guided by the specific requirements of the application. Professionals typically consider factors such as the fuse’s rated current, voltage rating, interrupting rating, and I²t value to ensure compatibility with the protected circuit. Littelfuse provides comprehensive technical documentation, including time-current curves and application notes, to assist engineers in selecting the optimal fuse for their system. The L25S012 is available in standard package configurations, including axial and surface-mount designs, to accommodate diverse mounting requirements. Proper sizing and coordination with upstream and downstream protection devices are critical to achieving a coordinated protection scheme that minimizes nuisance tripping while maximizing fault isolation. Littelfuse’s reputation as a trusted provider of circuit protection solutions is built on decades of innovation and industry leadership. With a global presence and a commitment to research and development, Littelfuse continues to set the standard for semiconductor fuse technology. The company’s dedication to quality is evident in its adherence to rigorous testing protocols and compliance with international standards, including UL, CSA, and CE certifications. By choosing the Littelfuse L25S012, engineers and system designers gain access to a fuse that not only meets but exceeds the demands of modern power electronics, delivering peace of mind and long-term reliability in even the most challenging applications. For professionals seeking a semiconductor fuse that combines advanced technology, consistent performance, and uncompromising quality, the Littelfuse L25S012 is the ideal choice. Whether protecting critical infrastructure, renewable energy systems, or industrial machinery, this fuse ensures that equipment operates safely, efficiently, and reliably—today and tomorrow.
  • Ultra-fast response time for semiconductor protection
  • High interrupting rating for fault isolation
  • Low let-through energy (I²t) for component safety
  • Compliant with UL 248 and IEC 60269 standards
  • Available in axial and surface-mount configurations

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
L25S Series
Type
Semiconductor Fuse
Package Weight (Imperial)
0.043 L
Package Weight (Metric)
0.020 kg
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20

C331156

Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20
Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8

1SCM8

Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8
Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.

LCC5

POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in

Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.