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Overvoltage Protection

Diodes, TVS, diode arrays, relays, surge protectors, SIDACtor® protection thyristors, and varistors provide overvoltage protection to PCBs, LED arrays, and other delicate electronics. The devices also help save power by switching current efficiently and limiting current leakage. Rely on Littelfuse products when designing, building, and servicing electrical systems.

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    Diodes - Overvoltage Protection

    Diodes can supplement the circuit protection work done by fuses. When used for overvoltage protection, diodes with high reverse voltage ratings and low ampere ratings ensure current flows just one way through a circuit. This prevents circuit overload and overheating. Littelfuse makes several of these essential safety devices.

    Automotive Diodes Overvoltage Protection

    Automotive Diodes Overvoltage Protection-MINI/ATO Diodes

    Use ATO® and MINI® automotive diodes from Littelfuse to ensure current flows only one way through circuits. Each of our automotive diodes has an ampere rating of 1 A and a high peak inverse voltage rating to dependably prevent current backflow.
    • Maximum power ratings of 0.25 W
    • Available with peak inverse voltages of 400 V or 1 kV
    • Operate at temperatures ranging from –40 ℃ to +125 ℃
    • Nickel-zinc–plated cold rolled steel terminals
    • Thermoplastic housings
    • RoHS compliant
    • Green housing helps identify MINI automotive diode with 1 kV peak reverse voltage
    • Cathode connector rotated at 90° helps identify ATO automotive diode

    Gas Discharge Tubes

    Reduce the risk of damage from short-lived and unpredictable voltage surges by installing durable gas discharge tubes (GDTs). The plasma-filled overvoltage protection devices absorb large amounts of current and redirect it to ground without producing frequencies that could incapacitate nearby components. These characteristics make GDTs essential surge protective devices for outdoor telecom equipment prone to lightning strikes. Littelfuse offers a broad selection of leaded and surface mounted GDTs for many applications. Each boasts a minimal footprint and low weight, and our squared GDT is among the smallest available.

    Gas Plasma Switches

    Gas plasma switches outperform solid state switches in ignition systems such as those for HID headlights that burn xenon. The specially designed gas discharge tubes release current in response to voltage surges. This makes them also useful as triggers in capacitive discharge ignition systems.
    • Two electrodes
    • Available with spark voltage ratings in the ranges of 200–255 V, 350–460 V, 528–627 V, and 704–896 V
    • Maximum load current of 50 mA
    • Available with switching frequencies of 25 Hz or 200 Hz
    • Capacitance of 1.4 pF
    • Certified lead-free and RoHS compliant
    • Ceramic chamber for plasma ensures durability
    • Highly resistant to moisture (MSL 1)
    • High switching speed optimizes performance of ignition transformers
    • Extremely high insulation resistance of 100 MΩ
    High Voltage

    High Voltage

    High voltage gas discharge tubes (GDT) provide overvoltage protection to components and circuits in electronic equipment. The GDTs contain plasma and discharge transient voltage surges from events like lightning strikes and inrushes of current at startup as heat. You will find these surge protective devices on power transmission lines and data cables, as well as in telecommunications equipment medical devices.
    • Available with a wide range of voltage ratings, from 75 V dc to 4 kV dc
    • Capacitance > 1 pF
    • UL Recognized
    • RoHS compliant
    • Suitable for use in sensitive equipment and high-frequency applications
    • Available in axial leaded, radial leaded, and surface mount configurations
    • Available with fail-short mechanisms
    • Ceramic–metal body ensures durability
    Low-to-Medium Surge

    Low-to-Medium Surge

    Low-to-medium surge gas discharge tubes (GDTs) also go by the name plasma surge protective devices. Developed to provide lightning protection to broadband telecommunications equipment, these GDTs also protect data cables and electrical power transmission lines. Littelfuse produces many sizes and types of low-to-medium surge GDTs. Our newer overvoltage protection devices are engineered to mount on the surface of printed circuit boards.
    • Available with a wide range of voltage ratings, from 72 V to 4 kV
    • Very fast-acting (e.g., surge rating of 2 kA 2/20 µs)
    • Available with low or ultra-low capacitance
    • Low insertion loss
    • Meet UL standards
    • Certified lead-free, halogen-free, and RoHS compliant
    • Ideal for overvoltage protection in equipment operating in the GHz range
    • Includes a crowbar device with low arc voltage
    • Available with optional fail-short mechanisms
    • Extremely robust and capable of withstanding multiple lightning strikes.
    • Compatible with automated and high-volume PCB manufacturing
    Medium-to-High Surge

    Medium-to-High Surge

    Medium-to-high surge gas discharge tubes (GDTs) also go by the name plasma surge protective devices. Developed to provide lightning protection to broadband telecommunications equipment, these GDTs also protect data cables and electrical power transmission lines. Littelfuse produces many sizes and types of medium-to-high surge GDTs. Our newer overvoltage protection devices are engineered to mount on the surface of printed circuit boards.
    • Fast-acting (e.g., surge rating of 12 kA at 8/20 µs)
    • Available with low or ultra-low capacitance
    • Low insertion loss
    • Meet UL standards
    • Certified lead-free and RoHS compliant
    • Ideal for overvoltage protection in equipment operating in the GHz range
    • Includes a crowbar device with low arc voltage
    • Available with optional fail-short mechanisms
    • Available with axial leads
    • Extremely robust and capable of withstanding multiple lightning strikes without declining in performance
    • Compatible with automated and high-volume PCB manufacturing

    Squared

    Squared gas discharge tubes (GDTs) mount on printed circuit boards to provide overvoltage protection to board components, circuits, and electrical equipment. The surge protective devices respond within picoseconds, using plasma to discharge excess voltage as heat. You will find the SPDs providing lightning protection to overhead power lines and protecting data cables from smaller overvoltage events. Discover the best surge suppressor for you application by consulting the Littelfuse Circuit Protection Product Selection Guide.
    • Surge capacities of between 1 kA 8/20 µs to 5 kA 8/20 µs
    • Wide ranges of operating voltages (e.g., 75 V dc to 600 V dc)
    • Very low to low capacitance (e.g., ≥ 0.5 pF, ≥ 1 pF)
    • Include crowbar devices with low arc voltages
    • Small footprints (e.g., 3.2×1.6×1.6 mm)
    • UL Recognized
    • Meet IEC and ITU standards
    • Certified lead-free and RoHS compliant
    • Capacitance does not vary with voltage, meaning responses to fast transient overvoltage events will not introduce noise across data or voice circuits
    • Available with optional fail-short mechanisms to remove blown GDTs from circuits
    • Available with a variety of mounting leads
    • Compatible with high-volume and automated PCB production processes

    Very High Surge

    Very high surge GDTs provide overvoltage protection to sensitive electronic components. Littelfuse makes two versions of these specialized gas discharge tubes. Our SL1021B GDT protect broadband equipment, and SL1026 GDTs protect railway equipment used for wireless communications, signaling, and remote control. Both of the surge protective devices exceed applicable standards for lightning protection, and both are optimized for mounting on the surface of printed circuit boards.
    • Wide range of current ratings, from 100 mA to 20 A
    • High interrupting ratings (e.g., 10 kA at 600 V ac)
    • Meet or exceed UL and IEC standards
    • Certified lead-free and RoHS compliant
    • Can connect to cables or mount on printed circuit boards
    • Fit easily into fuse blocks and panels
    • Fast-acting and time-delayed fuses available
    • Can supplement the operation of circuit breakers

    Polymer ESD Suppressors

    Polymer ESD suppressors protect electronics and people against harmful electrostatic discharges and other transient voltage surges such as lightning strikes. Littelfuse makes bidirectional ESD protection products for cables, data ports, USBs, cell phones, LCD and plasma screens, and antenna systems. We also produce XTREME-GUARD® ESD Protectors for automotive overvoltage protection applications. Durable enough to withstand thousands of shocks each hour for years on end, ESD suppressors ensure safe, reliable performance by electronic devices of all types.

    PESD Protection Device

    PESD protection devices protect high-frequency electronics from damage due to electrostatic discharges and transient voltage surges caused by handling, startup, shut down, and lightning strikes. The bidirectional devices made by Littelfuse handle 100 shocks per minute without failing. Smaller than gas discharge tubes and less likely to introduce noise than multilayer varistors, our thick film PESD protection devices serve in HDMI interfaces, LCD screens, and USB ports.
    • Available with operating voltages of 14 V or 24 V
    • Typical capacitance ratings of 25 pF
    • Typical response times below 1 ns
    • Typical withstand capabilities of 8 kV by contact and 15 kV through the air
    • Operate in a range of temperatures from –55 ℃ to +125 ℃
    • ELV compliant
    • Certified lead-free, halogen-free, and RoHS compliant
    • Help equipment pass IEC 61000-4-2 level 4 testing
    • Low leakage current ratings
    • Low clamping voltages
    • Compatible with reflow soldering processes
    PulseGuard ESD Suppressors

    PulseGuard ESD Suppressors

    Bidirectional PULSEGUARD® ESD suppressors use polymer composites to protect sensitive electronics from electrostatic discharges and other transient voltage surges. Designed primarily to provide supplemental protection to components of integrated circuits and printed circuit boards, these surge protective devices boast subminiature design. Their low profile and ability to withstand as many as a thousand pulses per minute make PULSE-GUARD ESD suppressors ideal choices for protecting high-speed data cables and data ports from ESDs created by human–machine interactions.
    • Rated at 12 V dc and 24 V dc
    • Repetitive surge capabilities up to 8 kV from contact and up to 15 kV through the air
    • Available with typical clamping voltage ratings from 40 V to 300 V
    • Ultra-low typical capacitance ratings (e.g., 50 pF, 70 pF)
    • Typical response times below 1 ns
    • Meet or exceed IEC 6100-4-2 and MIL-STD-883E standards
    • Certified lead-free and RoHS compliant
    • Low leakage current ratings
    • International standard packages
    • Compatible with pick-and-place board assembly processes
    • Compatible with reflow and wave soldering processes
    Xtreme Guard

    Xtreme Guard

    Bidirectional XTREME-GUARD® ESD suppressors protect sensitive electronics from damage due to electrostatic discharges and transient voltage surges caused by handling, start-up, shut down, and lightning strikes. Proven to withstand ESDs of up to 30 kV from contact or through the air, the surface mount devices are also capable of handling a thousand voltage surges per minute. The ESD protection devices boast ultra-low capacitance, meaning they introduce no noise into circuits. Their small size makes XTREME-GUARD ESD suppressors good choices for smartphones, notebook computers, and wearable devices.
    • Available with maximum operating voltages of 24 V dc or 32 V dc
    • Typical clamping voltages of 40 V dc
    • Ultra-low capacitance ratings (e.g., 0.04 pF, 0.09 pF)
    • Typical response times below 1 ns
    • Typical withstand capabilities of 30 kV by contact and 30 kV through the air
    • Operate in temperatures ranging from –65 ℃ to +125 ℃
    • Certified lead-free, halogen-free, and RoHS compliant
    • Exceed IEC 61000-4-2 standards
    • Ultra-low current leakage ensures minimal power loss
    • Compatible with reflow soldering processes
    • Compatible with pick-and-place PCB assembly processes

    SIDACtor® Protection Thyristors

    SIDACtor protection thyristors prevent damage from transient voltage surges due to lightning strikes and ac power crosses. The surge protective devices also protect people and electronics from electrostatic discharges generated by human–machine interactions. These specialized silicon diodes for alternating current (SIDACs) join LED protectors as circuit protection products offered by Littelfuse. Consult our catalog to find a solution for your broadband, baseband, cellular, DS1, LCAS, SLIC, voice, or lighting application.

    Automotive SIDACtor® Protection Thyristors

    Automotive SIDACtor® Protection Thyristors

    Automotive-quality SIDACtors provide overvoltage protection to sensitive electronics for in-vehicle data cables and infotainment systems. The AEC-Q101–qualified surge protective devices boast fast responses following voltage surges from lightning strikes, as well as equipment startup and shutdown. Littelfuse makes several versions of these silicon diodes for alternating current. Each is designed to mount on the surface of a printed circuit board. Each can also withstand multiple surges in rapid succession.
    • Available with a broad range of dynamic resistance voltage (VDRM) ratings, from 6 V to 275 V
    • Available with a broad range of switching voltage (Vs T-R) ratings from 25 V to 350 V
    • Comply with GR-1089, IEC 6100-4-5 2nd ed., ITU K.20/21, TIA-968, YD/T 95, YD/T 993, and YD/T standards
    • UL 497B Recognized as an isolated loop circuit protector
    • Certified lead-free, halogen-free, and RoHS compliant
    • Surge capabilities do not degrade due to multiple surges within ratings
    • Low capacitance and low dv/dt
    • Fail as short circuits when surged in excess of capacities
    • International standard DO-214AA package
    Connectivity SIDACtor® Protection Thyristors
    Connectivity SIDACtor® Protection Thyristors

    Connectivity SIDACtor® Protection Thyristors

    Solid state SIDACtor® protection thyristors protect telecommunications equipment, data cables, and switching devices from transient voltage surges. Since the silicon diodes for alternating current get used in many ways, Littelfuse makes what we call connectivity SIDACtors optimized for specific applications. For outdoor equipment prone to lightning strikes, we offer high-exposure surge protection thyristors. We also produce more sensitive surge protective devices designed for use with subscriber line interface circuits (SLICs), line circuit access switches (LCASs), and broadband relays.
    • Wide range of Vdrm T-R ratings up to 600 V
    • Wide range of Vs T-R ratings up to 700 V
    • Off-state capacitance ratings generally below 50 pF
    • Bidirectional
    • Meet international standards, including TIA-968, ITU K.20/21, GR 1089 Inter-building, GR 1089 Intra-building, IEC 61000-4-5, and YD/T 1082
    • Lead-free and RoHS compliant
    • Small footprints
    • Voltage surges withing rated capacity will not degrade a device’s performance
    • Most version fail as short circuits when voltage surges exceed the device’s capacity

    High Exposure Surge Protection

    High Power SIDACtor® protection thyristors offer ideal solutions for suppressing transient voltage surges in areas with high exposure to lightning strikes. Littelfuse makes several versions of these thyristors, including devices optimized to provide primary surge protection and meet international standards such as UL 497, GR-947, and ITU K.28. Other thyristors can protect ac power lines or outdoor telecommunications and networking equipment. We supply each of these thyristors in compact packages that mount easily on printed circuit boards and with peak repetitive forward voltage ratings as high as 550 V.
    • Vdrm T-R from 5 V to 550 V
    • Vs T-R from 25 V to 700 V
    • Is(max) of 800 mA
    • Hold currents of 50 mA or 150 mA
    • Maximum off-state capacitance ratings below 650 pF
    • Lead-free, halogen-free, and RoHS compliant
    • Low voltage overshoot
    • Low on-state voltage
    • Fail to short circuit
    • High holding current versions available
    • Performance does not degrade over time or with use

    Wafer & Bare Die

    Littelfuse offers TVS diodes and SIDACtor® protection thyristor wafers and bare dies to provide overvoltage and ESD protection for a range of applications. We can partner with you to create devices that meet the unique needs of your equipment.

    PLED-LED Lighting

    Specially designed SIDACtor protection thyristors made by Littelfuse ensure LED light strings continue operating when individual bulbs fail as open circuits. Our PLED—short for “LED protector”—products shunt current around shorted bulbs while also providing ESD, EFT, and transient voltage surge protection. We offer several different types of PLEDs, including devices for outdoor use that meet international standards for lightning protection and devices for use in light ballast originally installed to support fluorescent fixtures.
    • Available with a very wide range of maximum repetitive peak forward voltage ratings, from 6 VDRM to 340 VDRM
    • Available with maximum breakdown voltage ratings from 16 V to 430 V
    • Low hold current ratings from 5 mA to 30 mA
    • Responses times of approximately 100 ns
    • Certified halogen-free and RoHS compliant
    • Automatically reset after the power cycle
    • Maximum heat dissipation makes PLEDs good choices for densely packed printed circuit boards
    • Subminiature international standard packages
    • Smaller than silicon-controlled rectifiers
    • Less prone to failure due to current overload than Zenner diodes
    • Compatible with reflow soldering processes

    Surge Protective Modules & Devices

    Protecting electrical equipment from transient voltage surges prevents outages and reduces maintenance. Littelfuse offers several surge protectors to limit damage from lightning and overvoltage that may occur when equipment is switched on. Our varistor modules provide overvoltage protection for outdoor equipment and LEDs. Our globally compliant Type 2 SPDs plug in to generators, motors, and telecom and computer equipment. Consult our Surge Protection Devices Catalog to find your best solution.

    DIN Rail

    DIN Rail surge protective devices (SPDs) are engineered to snap or bolt easily onto nonconducting rails or supports inside equipment cases. Like all Littelfuse SPDs, DIN Rail devices safeguard electronic components against damage from transient voltage surges, especially those occurring during equipment startup and shutdown. Installing SPDs brings equipment into compliance with electrical codes, limits downtime, and reduces maintenance costs.

    AC Voltage

    DIN Rail-AC Voltage

    The Littelfuse surge protective module and device portfolio includes several DIN rail-mounted ac voltage Type 2 surge protective devices (SPDs) that are globally compliant and cost-effective. These SPDs are designed to protect electrical equipment from transient overvoltage or surge events, mitigating costly damage and downtime. Browse the Littelfuse selection of DIN-rail mountable ac voltage SPDs for your specific needs and requirements.
    • Input voltages from 60 V to 600 V
    • Voltage protection ratings from 330 V to 2.5 kV
    • Voltage protection levels up to 4 kV
    • SCCRs of up to 200 kA
    • SPST output circuitry
    • No additional overcurrent protection devices are required when 3-phase DIN rail-mounted Type 2 SPDs are used in UL applications
    • Thermal protection for internal circuits
    • 1-, 2-, 3-, and 4-pole versions available
    • Capable of clamping
    • Withstand high-energy transients
    Photovoltaic

    DIN Rail-Photovoltaic

    Littelfuse offers DIN-rail mounting in its Surge Protective Modules and Devices product portfolio, which includes the photovoltaic SPD2 PV series. These DIN-rail mountable, Type 2 SPDs are designed to protect equipment from transient overvoltage events. They are UL recognized and EN60715 compliant, IP20 finger safe, and provide thermal protection to eliminate catastrophic failure. They fit a 35 mm DIN rail with an interlocking tab to withstand vibration. They also feature a visual life indicator.
    • Thermal protection
    • IP20 protection rating
    • Pluggable modules
    • DIN-rail mounting
    • Solar applications
    • No additional overcurrent protection devices required
    LED Lighting Surge Protective Devices

    LED Lighting Surge Protective Devices

    rge protection modules principally protect outdoor safety and commercial lighting from damage due to lightning strikes. Littelfuse offers several versions of these specialized surge suppressors, including one (LSP05GX) specifically for use in Europe. Each module meets or exceeds regulatory and industry standards while relying on thermally protected varistors to direct voltage surges to ground. Our overvoltage protection modules also include thermal disconnect devices to prevent fires when varistors fail from overheating. You will find our modules in traffic lights, tunnel lighting, and business signs.
    • Voltage operating ratings of 120 V ac to 480 V ac
    • Maximum lightning surge current discharge capacities of 10 kA 8/20 µs or 20kA 8/20 µs
    • Waterproof and dustproof ratings of IP66
    • Meet or exceed UL, EN, US DOE, ANSI, and IEEE standards for lightning protection
    • Bidirectional polarity
    • RoHS compliant
    • Include or can be wired to indicator lights that alert maintenance personnel that varistors have failed and require replacement
    • Double insulation on cables keeps modules in circuit following lightning strikes
    • Can be configured for use in series or in parallel
    • Sealed to permit use in areas with high concentrations of dust and high likelihoods of heavy rain
    Panel Mount

    Panel Mount

    Install these Type 1 and Type 2 NEMA-style panel-mounted surge protective devices (SPDs) on the load side of circuit breakers to prevent transient voltage surges from damaging sensitive electronics. Easily replaced without opening equipment cases, the SPDs also offer the benefits of providing excellent short-circuit protection.
    • Input voltages from 60 V to 600 V
    • Maximum surge current ratings of 50 kA and 130 kA
    • Nominal current ratings of 20 kA
    • SCCRs of 200 kA
    • Operate at temperatures up to +85 °C
    • UL Listed
    • REACH and RoHS compliant
    • Direct protection for line to neutral (L-N), line-to-ground (L-G), and neutral to ground (N-G) circuits
    • Constructed from thermally protected stacked high-energy metal oxide varistors (MOVs)
    • Available with audible alarms
    • LED status indicators
    • Capable of clamping
    • Withstand high-energy transients
    • Compact designs

    TVS Diode Arrays

    TVS diode arrays protect electronics from damage due to transient voltage surges and electrostatic discharges (ESDs). Littelfuse offers a variety of these surge protective devices (SPDs) in SOIC, DIP, flipchip, and other designs. Our lightning SPDs direct massive voltage surges from lightning strikes on outdoor equipment to ground. Our ultra-low capacitance TVS diodes provide ESD protection to data ports and cables. We also make SPDs specifically for automotive applications. Find your solution in our Circuit Protection Products Selection Guide.

    Automotive - TVS Diode Arrays

    Automotive – TVS Diode Arrays

    Preventing transient voltage surges from damaging electrical systems in commercial and passenger vehicles has always presented a challenge. AEC-Q–qualified automotive TVS diode arrays made by Littelfuse offer cost-effective and highly adaptable solutions. Our TVS diode arrays provide lightning, ESD, and fast transient protection. The devices are PPAP compatible, and we offer unidirectional, bidirectional, single line, multiple line, and low-capacitance (e.g., 0.32 pF) options. All our arrays come in compact packages suitable for mounting on printed circuit boards via pick-and-place assembly.
    • Reverse standoff voltage (Vrr) ratings from to 5 V to 76 V
    • Power ratings from 200 W to 7 kW
    • Peak pulse current ratings (Ipp at 10×1000 µs) from 800 mA to 103 A
    • Typical response times under 1 ns
    • Plastic bodies with UL 94 flammability ratings of V-0
    • Matte tin-plated copper leads
    • Meet IEC 61000-4 standards
    • Certified lead-free, halogen-free, and RoHS compliant
    • International standard packages
    • Unipolar and bipolar versions available
    • Low inductance
    • Excellent clamping capability
    • International standard packages
    Connectivity - TVS Diode Arrays

    Connectivity – TVS Diode Arrays

    Connectivity TVS diode arrays are optimized to protect circuits from damage due to transient voltage surges caused by lightning strikes. They also offer general overvoltage protection and protection against surges caused by electrostatic discharges (ESDs) and by turning equipment on and off. Littelfuse makes these lightning protection solutions for automotive (AEC-Q–qualified), broadband, power over ethernet (PoE), medical, and consumer electronics applications. We also offer specially designed connectivity TVS diode arrays with low capacitance ratings and for use with circuits that carry high voltages.
    • Standoff voltage ratings from 1.1 V to 58 V
    • Reverse leakage current ratings from 0.1 µA to 25 µA
    • Lightning immunity up to 40 A at 8/20 µs
    • ESD protection ratings up to 30 kV due to contact and through the air
    • Meet IEC 6100-4 standards
    • Certified lead-free, halogen-free, and RoHS compliant
    • International standard packages
    • Unidirectional and bidirectional versions available
    • Low capacitance
    • Low clamping voltage ratings

    General Purpose

    Find the electrostatic discharge (ESD) protection solutions your electronic equipment requires. Littelfuse maintains a large portfolio of general purpose TVS diode arrays that meet international standards for preventing damage from transient voltage surges, electronic fast transients, and other overvoltage events. We offer unidirectional and bidirectional devices, and many of our general purpose TVS diode arrays are AEC-Q–qualified for use in automotive applications. We also provide devices with ultra-low capacitance ratings and devices optimized for use with circuits that carry high voltages.
    • Standoff voltage ratings from 3.3 V to 60 V
    • Reverse leakage current ratings from 0.005 µA to 100 µA
    • Lightning immunity up to 30 A at 8/20 µs
    • ESD protection ratings up to 30 kV due to contact and through the air
    • Meet IEC 6100-4 standards
    • Certified lead-free and RoHS compliant
    • International standard packages
    • Unidirectional and bidirectional versions available
    • Low capacitance
    • Low clamping voltages
    • Subminiature international standard packages
    Industrial & Medical

    Industrial & Medical

    Use general purpose, low-capacitance, and ultra-low–capacitance TVS diode arrays to protect personnel, patients, and sensitive electronic equipment in medical and industrial settings. Littelfuse offers more than a hundred types of TVS diode arrays in miniature and subminiature packages. Our transient voltage surge suppressors withstand repeated electrostatic discharges, lightning strikes, and overvoltage events during start up and shut down of up to 30 kV. Each device functions without introducing excess noise into circuits, and several of our TVS diodes arrays also provide EFT and supplemental overcurrent protection.

    Low & Ultra-Low Capacitance

    Low & Ultra-Low Capacitance

    High-speed data cables, telecommunication circuits, touchscreens, and audio and video ports require protection from transient voltage surges, electrostatic discharges (ESDs), and other overvoltage events. The devices that provide this protection must work without distorting incoming and outgoing signals. Littelfuse offers ideal solutions in the form of low-capacitance and ultra-low–capacitance TVS diode arrays. Available in many sizes and shapes, and with unidirectional or bidirectional performances, these devices have capacitance ratings from 0.13 pF to 1 pF. Several are AEC-Q–qualified for automotive applications.
    • Standoff voltage ratings from 300 mV to 28 V
    • Standoff voltage ratings from 300 mV to 28 V
    • Lightning immunity up to 4 A at 8/20 µs
    • ESD protection ratings up to 30 kV due to contact and through the air
    • Meet IEC 6100-4 standards
    • Certified lead-free and RoHS compliant
    • International standard packages
    • Unidirectional and bidirectional versions available
    • Halogen-free versions available
    • Devices available with one, two, or four channels
    • Subminiature international standard packages

    TVS Diodes

    Transient voltage suppressor (TVS) diodes defend against damage from overvoltage events by responding within picoseconds to shunt current to ground. The classic example of TVS diode use is protecting outdoor telecom equipment from lightning strikes. Littelfuse produces surface mount and leaded diodes and TVS diode arrays for that, as well as TVS diodes for cars, personal electronics, data cables, and household appliances. Consult our Circuit Protection Selection Guide to guide your search for a solution.

    Automotive – TVS Diodes

    Automotive TVS diodes provide overvoltage protection to sensitive electronic components in passenger cars and commercial vehicles. The surge suppressors also protect against electrostatic discharges. Designed to mount directly on printed circuit boards with lead-free solder, these automotive diodes meet international standards for performance and durability in under the hood operating environments. They withstand lightning strikes while also responding to smaller current surges.
    • Low inductance
    • Excellent clamping capacity
    • Most diodes are AEC-Q101–qualified
    • Halogen-free, lead-free, and RoHS compliant
    • Typically respond in less than 1 ps
    • Provide EFT protection
    • Several diodes feature passivated glass chip junctions to minimize current leakage
    • Low-profile designs reduce space needed for PCBs and integrated circuits
    Avionics & High Reliability

    Avionics & High Reliability

    Rapid and consistent transient voltage surge suppression (TVSS) matters greatly in aviation. Aircraft, radar, landing systems, and onboard electronics such as FADEC, sensors, and fly-by-wire systems can fail catastrophically following a lightning strike or other voltage surges. Littelfuse meets the demand for high-reliability TVS diodes by producing several lines of overvoltage protection devices that have been screened and proven for avionics applications. All our high-reliability TVS diodes for avionics are military grade, and several employ Foldbak technology to deliver superior clamping.
    • Vr (Vso) from 5 V to 345 V
    • Vbr(max) from 5 V to 423 V
    • Power ratings from 400 W to 30 kW
    • Ipp from 2.2 A to 606 A (10×1000µs)
    • Response times below 1 ps
    • Meet IEC 6100-4-2 standards for providing ESD protection of up to 30 KV through the air and 30 kV by contact
    • UL94 flammability ratings of V-0
    • Lead-free, halogen-free, and RoHS compliant
    • Custom screening options available for enhanced reliability
    • Excellent clamping capabilities
    • Space-saving low-profile packages
    • Versions available with built-in strain relief
    • Some versions fail to short circuit
    High Power

    High Power

    High power TVS diodes provide dependable protection against transient voltage surges in electrical systems that already carry high current loads. Littelfuse offers these types of TVS diodes with peak pulse capabilities as high as 30 kW (10/1000µs) and peak pulse current ratings as high as 3 kA. Several employ Foldbak technology to deliver improved clamping, and all come in subminiature packages that save space on printed circuit boards. You can choose unipolar or bipolar TVS diodes with axial leads or without leads.
    • Available with collector–emitter continuous voltage ratings of 1.7 kV dc to 6.5 kV dc
    • Available with collector–emitter saturation voltage ratings of 900 V to 3.6 kV
    • Available with repetitive peak collector current ratings of 280 A to 6 kA
    • Reverse recovery times typically below 1.2 µs
    • High temperature tolerance, with devices operating in the range of –40 ℃ to +125 ℃
    • Absence of wires and soldering reduces risks for mechanical fatigue to practically zero
    • Low inductance from gate and emitter connections prevents short circuits
    • International standard packages

    Leaded

    Leaded TVS diodes mount on printed circuit boards, inside data ports, and on cable connectors to protect semiconductors and other electronic components from transient voltage surges. Littelfuse offers these diodes with peak pulse power capabilities between 400 W at 10/1000µs and 1.5 kW at 10/1000µs. Our overvoltage protection devices come in international standard subminiature packages and excel at proving lightning protection.
    • Vr (Vso) from 5 V to 512 V
    • Vbr(max) from 7.14 V to 660 V
    • Power ratings from 400 W to 1.5 kW
    • Ipp from 500 mA to 144.8 A (10×1000µs)
    • Response times below 1 ps
    • Meet IEC 6100-4-2 standards for providing ESD protection of up to 30 KV through the air and 30 kV by contact
    • UL94 flammability ratings of V-0
    • Lead-free, halogen-free, and RoHS compliant
    • Custom screening options available for enhanced reliability
    • Excellent clamping capabilities
    • Space-saving low-profile packages
    • Some versions fail to short circuit

    Surface Mount

    Surface-mount TVS diodes protect semiconductors and other electronic components on PCBs, in data ports, or inside cable connectors from transient voltage surges, ESDs, and EFTs. Littelfuse supplies these overvoltage protection devices in many different types of subminiature packages that are compatible with lead-free soldering processing. The diodes have peak pulse ratings ranging from 200 W at 10/1000µs to 4 kW at 10/1000µs.
    • Vr (V so) from 3.3 V to 553 V
    • Vbr(max) from 4.3 V to 682 V
    • Power ratings from 200 W to 4 kW
    • Ipp from 500 mA to 326 A (10×1000µs)
    • Response times below 1 ms
    • Meet IEC 6100-4-2 standards for providing ESD protection of up to 30 KV through the air and 30 kV by contact
    • UL94 flammability ratings of V-0
    • Lead-free, halogen-free, and RoHS compliant
    • Excellent clamping capabilities
    • Low inductance
    • Several versions fail to short circuit
    • Space-saving low-profile packages
    • Versions available with built-in strain relief
    Wafer & Bare Die

    Wafer & Bare Die

    Surface-mount TVS diodes protect semiconductors and other electronic components on PCBs, in data ports, or inside cable connectors from transient voltage surges, ESDs, and EFTs. Littelfuse supplies these overvoltage protection devices in many different types of subminiature packages that are compatible with lead-free soldering processing. The diodes have peak pulse ratings ranging from 200 W at 10/1000µs to 4 kW at 10/1000µs.
    • Vr (V so) from 3.3 V to 553 V
    • Vbr(max) from 4.3 V to 682 V
    • Power ratings from 200 W to 4 kW
    • Ipp from 500 mA to 326 A (10×1000µs)
    • Response times below 1 ms
    • Meet IEC 6100-4-2 standards for providing ESD protection of up to 30 KV through the air and 30 kV by contact
    • UL94 flammability ratings of V-0
    • Lead-free, halogen-free, and RoHS compliant
    • Excellent clamping capabilities
    • Low inductance
    • Several versions fail to short circuit
    • Space-saving low-profile packages
    • Versions available with built-in strain relief

    Varistors

    Varistors provide transient voltage surge suppression in consumer electronics, household appliances, telecom equipment, and computers. The overvoltage protection devices shield semiconductors and other components from damage due to lightning strikes, and electrostatic discharges. Littelfuse produces metal oxide varistors (MOVs) in surface mount, thermally protected, and radial leaded configurations. In addition to AUMOV®, UltraMOV®, and TMOV® devices, we design specialty varistors to customers’ specifications.

    2-Pro Devices

    2PRO® devices combine PolySwitch® polymeric positive temperature coefficient (PPTC) resettable fuses and metal oxide varistors (MOVs). The devices provide overcurrent, overvoltage, and overtemperature protection in compact devices, allowing electronic equipment manufactures to simplify PCB design. 2PRO devices protect electronics from lightning, electrostatic discharge, short circuits, electromagnetic interference, and voltage surges. Places you will find 2PRO devices include networking equipment, data centers, power supplies, security systems, household appliances, and smart meters.
    • Available with hold current ratings from 150 mA to 750 mA
    • Available with trip current ratings from 300 mA to 1 A
    • Available with minimum resistance ratings from 370 m Ω to 6.5 Ω
    • Certified halogen-free and RoHS compliant
    • Combining PPTCs and MOVs simplifies circuit design, reduces device count, and reduces MOV failures due to overheating
    • Use helps equipment comply with UL 60950, IEC 6100-4-4, and IEC 6100-4-2 standards
    • Use in telecom equipment facilitates compliance with surge tests defined under TIA-968-A, IEC 60950, ITU-T K.20, and ITU-T K.21
    • Designed for wave soldering

    Industrial High Energy

    Industrial high energy varistors provide transient voltage surge suppression (TVSS) and general circuit protection. As heavy-duty bidirectional metal-oxide varistors (MOVs), these surge protective devices install in oil-drilling, mining, and outdoor power equipment to prevent damage from lightning strikes. The MOVs also install in ac power meters, on DIN rails, and in uninterruptible power supplies. Dependable TVSS is essential when even small voltage surges can destroy sensitive components and cause costly outages.
    • 25–40 KA at 8/20 µs surge capacities
    • Available with a wide range of maximum operating voltage ratings, from 102 V dc to 3.5 kV dc
    • Available with a wide range of energy absorption (WTM) capabilities, from 40 J to 1.05 J
    • Certified lead-free and RoHS compliant
    • Custom voltage ratings available
    • No derating up to 85 ℃
    • Rigid terminals for secure mounting and soldering
    • Suitable for paralleling

    Multilayer Varistors

    Multilayer varistors combine overvoltage, electrostatic discharge (ESD), and electric fast transient protection in a single, surface mount device. these ultra-low–profile surge protective devices typically protect printed circuit board and integrated circuit components. Because multilayer varistors perform more than one function, they can replace several larger discrete surge suppressors and signal filtering devices on PCBs. Littelfuse offers several types of multilayer varistors, including devices specifically designed for use in passenger cars and commercial vehicles.
    • Wide range of voltage ratings (e.g., 3.5 V to 48 V)
    • Very low to low capacitance (e.g., 3 pF to 22 pF)
    • Inherently bidirectional clamping
    • Meet IEC 6100-4-2 standards for electromagnetic compliance
    • Automotive devices meet AEC-Q200 standards
    • RoHS compliant
    • Can be used to protect analog and digital circuits
    • Specifically designed to mount on the surface of PCBs
    • Compatible with reflow and wave soldering procedures
    • Operate in a wider temperature range than do Zenner diodes
    • Reduce need for discrete surge protective devices
    • Absence of plastic housings translates into smaller footprints and higher UL flammability ratings
    Radial Leaded - Varistors

    Radial Leaded – Varistors

    Radial leaded varistors protect electronic components and integrated circuits from transient voltage surges and electrostatic discharges. Littelfuse makes several of these surface mounted surge protective devices for specific uses. For instance, our AUMOV® radial leaded metal oxide varistors are AEC-200–qualified for automotive applications. Our Hi-Rel devices meet military standards for high reliability, and TMOV® varistors employ patented technology to ensure thermal protection from spikes in heat due to voltage surges. UltraMOV® devices are optimized to protect ac power lines.
    • Available with maximum ac voltage operating ratings from 4 V ac to 1 kV ac
    • Available with maximum dc voltage operating ratings from 5 V dc to 825 V dc
    • Available with transient energy ratings (Wtm) from 100 mJ to 890 J
    • Peak pulse current capabilities up to 22 kA
    • UL Recognized in Canada and the United States
    • Certified lead-free, halogen-free, and RoHS compliant
    • Available with custom voltage ratings
    • Inherently hardened against radiation
    • Ultra-high coating insulation resistance of at least 1 GΩ
    • Available in a range of disk and box sizes from 3 mm to 25 mm
    • Compatible with lead-free wave soldering processes
    Specialty

    Specialty

    Littelfuse makes two types of specialty surface mount varistors for suppressing low-energy transient voltage surges and protecting electronics from electrostatic discharges. Our MA series metal oxide varistors feature radial leads and give users the choice of standard or tightened clamping voltage ratings. Our RA series surge protective devices have inline leads and feature seating planes that ensure secure mounting on printed circuit boards. This mechanical stability makes the MA series specialty varistors good choices for overvoltage protection in industrial and military applications subject to strong vibrations.
    • Available with maximum ac voltage operating ratings from 4 V ac to 264 V ac
    • Available with maximum dc voltage operating ratings from 5.5 V dc to 369 V dc
    • Available with transient energy ratings (Wtm) from 40 mJ to 23 J
    • Peak pulse current capabilities up to 1.2 kA
    • Certified lead-free, halogen-free, and RoHS compliant
    • No derating until ambient temperatures rise above the upper limits of devices’ nominal operating temperatures
    • Available with axial leads or in-line leads
    • Subminiature international standard packages
    • Compatible with high-volume chip assembly processes
    Surface Mount - Monolithic Varistors

    Surface Mount – Monolithic Varistors

    The surface mount monolithic varistor family of products offered by Littelfuse includes metal oxide varistors with solderable leads and MOVs without leads. Supplied in subminiature packages, each of these MOVs can provide protection against transient voltage surges continuously across ac lines and, as needed, to dc circuits. Varistors in the SM20 series are particularly well-suited to provide load dump protection in automotive applications.
    • Maximum operating dc voltage ratings from 18 V dc to 900 V dc
    • Maximum operating ac voltage ratings from 18.9 V ac to 510 V ac
    • Off-state capacitance ratings as low as 45 pF
    • RoHS compliant
    • Compact, low-profile packages save space on printed circuit boards
    • Withstand pulse currents up to 1.2 kA
    • No derating at normal operating temperatures (e.g., below +65 ℃)
    Thermally Protected

    Thermally Protected

    Thermally protected varistors integrate metal oxide varistors with thermally activated elements to provide overvoltage protection. By opening in response to heating from overvoltage events, the surge protective devices (SPDs) also prevent arcs and fires. Typical applications for the thermal cutoff devices include power strips, inverters, and uninterruptible power supplies. Littelfuse makes several versions of these innovative SPDs, including one with a semiconductor fuse. Find a solution by consulting our Circuit Protection Product Selection Guide.
    • Available with a wide range of operating voltages, from 75 V ac to 750 V ac
    • Available with a wide range of surge current ratings, from 6 kA 8/20 µs to 75 kA 8/20 µs
    • UL recognized
    • Certified lead-free, halogen-free, and RoHS compliant
    • Configured as square, tubular, and radial leaded surface mount SPDs
    • Optional leads can connect to indicators that show varistors have reached the end of their life and require replacing
    • Facilitate compliance with UL 1449 standard on use of SPDs
    • Integration of surge suppressor with thermal cutoff produces less inductance across a PCB than would using discrete components
    • Wave solderable