Selection Guide - Littelfuse

1 Circuit Protection ProductsSelection GuideA Guide to selecting the right protection components for your applications 2020 Littelfuse , Circuit Protection Technologies4 5 Overcurrent Protection Solutions6 Overvoltage Protection Solutions7 ESD Suppression Solutions8 Applications9 11 Common Circuit Threats and Protection Solutions12 13 Fuses14 16 Fuseholders17 Surface Mount PPTC Devices18 19 Radial Leaded PPTC Devices19 20 Battery PPTC Devices20 Battery Mini-Breakers (Thermal Cutoff Devices)21 Telecom PPTC Devices22 Varistors23 24 Gas Discharge Tubes24 26 PulseGuard ESD Suppressors26 TVS Diode Arrays27 29 TVS Diodes29 31 PLED Bypass Protectors32 33 SIDACtor Protection Thyristors33 35 About this guideThis Guide provides a summary of key circuit protection consideration factors, descriptions of the technologies Littelfuse offers, and product Selection tables.

2 It is designed to help you quickly find a protection solution appropriate to your , descriptions, and illustrative material in this literature are as accurate as known at the time of publication, but are subject to changes without notice. Visit for more with Confidence Supported by our Deep Application Expertise and Extensive 3 Littelfuse : Everywhere, Every Day Founded in 1927, Littelfuse has become the world s most respected circuit protection brand, with well-established and growing platforms in power control and sensing technologies. Today, we are a global company, offering a diverse and extensive product portfolio fuses, semiconductors, polymers, ceramics, relays, sensors, and more serving the electronics, automotive, and industrial markets. Each is manufactured to exacting quality standards and backed by an unwavering commitment to technical support and customer history of innovation, combined with our customer-first culture, drives us to collaborate with you to develop safer, more reliable products that are energy efficient and compliant with global regulations.

3 We will partner with you to solve complex problems wherever electrical energy is used, bringing design, engineering, and technical expertise to deliver business results. Why Choose Littelfuse Littelfuse is the global leader in circuit protection are the only company to offer all of the pertinent circuitprotection technologies, with products that can be used invirtually everything that uses electrical energy. Complementing our wide portfolio of circuit protection products is a global network of design and technical support expertise. We offer decades of design experience to help you addressapplication challenges and achieve regulatory Single SourceLittelfuse offers an extensive circuit protection product design forward-thinking, application-specific solutions toprovide assurance that your most demanding requirements will be met. Our goal is to provide the most complete range of options so that you will not have to SupportLittelfuse can help ensure that your products will withstand mostcommon threats repeatedly and will fail safely under extremecircumstances.

4 We can serve as an independent source to provideassistance as you design by offering lab testing capabilities forcustomer applications. This testing includes industry-specificrequired power fault and Electrostatic Discharge (ESD) / Electrically Fast Transients (EFT) / lightning surge KnowledgeFor over 90 years, Littelfuse has maintained a focus on circuit protection,and we will continue to adapt as technologies evolve. Engineers andcircuit designers around the world have come to rely on Littelfuseproducts and application knowledge to support their designs. Global SupportLittelfuse stays close to customers. With manufacturing, lab, and designfacilities located around the globe, application knowledge and technicalsupport are locally available. Also, we offer a network of regionalcustomer support offices and hundreds of independent authorizeddistributor contacts to assist you.

5 Visit tofind local support near Compliance ExpertiseMost Littelfuse products comply with a wide range of applicable industry and government guidelines as well as our own rigorous quality and reliability criteria. We continually look forward and adapt to changing requirements so that our products will comply with industry- specific national and international standards, such as CCC, CSA, IEC, IEEE, ISO, ITU, Meti, RoHs, Telcordia, TIA, and many ExcellenceWith our global manufacturing footprint, Littelfuse is firmly committed to manufacturing quality products at a competitive price. We build quality into our products and services, striving for zero defects in everything we do, thereby reducing cost and increasing your total satisfaction. We strive to exceed your expectations every AssuranceOur global manufacturing facilities abide by strict qualityassurance requirements and hold the following qualitymanagement system registrations: ISO 9001 ISO14001 IATF 16949 2020 Littelfuse , Features and Protection CharacteristicsWhen / Where Typically UsedSurge Energy Rating RangeTypical Voltage Clamping SpeedsTypical Capacitance/Insertion LossMounting/Size/ Packaging OptionsOvercurrent Protection TechnologiesFusesCompletely stops current flow,which helps to identify faults;Wide range of optionsUltimate protection for sensitive/expensive/critical componentsLow through Very HighNot applicableSeries impedance measured in nHVery Extensive Range of OptionsPPTC DevicesResettable.

6 No devicereplacement needed after mostcommon overcurrent eventsWhere overcurrent events may occur often, and continuous uptime desired Low through HighNot applicableSeries resistance measured in ohmsSurface Mount, Radial Leaded, Axial StrapOvervoltage Suppression TechnologiesMulti-Layer Varistors (MLVs)Compact and capable of handling significant surges for their sizeESD(1) and EFT(2) suppression insmaller and portable electronicsLow through MediumModerateHighMiniature Surface MountMetal-Oxide Varistors (MOVs)Capable of withstanding veryhigh energy transients;Wide range of options Appliance, industrial, and very high energy suppression applicationsMedium through Very HighModerateHighRadial Leaded, Industrial TerminalGDTsSwitches that turn to on state and shunt overvoltage to ground using a contained inert gas as an insulatorProtection of telecom equipment from lightning surgesMedium through HighFastLowSurface Mount, Axial Leaded, 2/3 Lead RadialPulseGuard ESD SuppressorsExtremely low capacitance;Fast response time;Compact sizeESD suppression; Ultra-fast reaction;Low signal distortionLowModerateLowMiniature Surface MountPLED LEDP rotectorsShunt function bypasses open LEDs; ESD and reverse power protectionHigh brightness outdoorLED lighting applicationsLow Very FastMediumMiniature Surface MountTVS Diode ArraysLow capacitance/low clamping voltage;Compact sizeESD suppression; Low distortion.

7 Ideal for I/O interfaces and digital and analog signal linesLow through MediumVery FastLowExtensive range of surface mount optionsTVS DiodesFast response to fast transients;Wide range of options: No wear out mechanismSemiconductor protection;Telecom I/O interfaces, electronics, industrial equipment, and automotive electronicsMedium through HighFastMediumAxial Leaded, Radial Leaded, Surface MountSIDACtor Protection ThyristorsDesigned to comply with stringent telecom/datacom networking and industrial AC power surge protection standards; No wear out mechanism, precise trigger voltage, and very low VtTelecom/datacom and networking applications, industrial equipmentMedium through HighVery FastMedium - LowExtensive range of surface mount and through-hole optionsCircuit Protection Technologies(1) ESD Electrostatic Discharge(2) EFT Electrical Fast 5 Fuses and Holders Fuses Full range including surface mount, axial, glass or ceramic , thin-film or Nano2 style, fast- acting or Slo-Blo Used in applications that require a fuse to be easily mounted to a Printed Circuit Board (PCB), but real estate is scarce.

8 Clips are also ideal for high-current applications, allowing for better heat management of the fuse. They are the most economical solution. Blocks An alternative solution to clips but with easier placement on the PC board during manufacturing. In some instances, blocks may provide insulation to the side ears of the clips. In addition to being through-hole, blocks can also be screwed or riveted in The ideal solutions for those applications that require the cartridge fuse to be protected, providing a shock-safe environment. Panel-mount holders allow for easy replacement of the fuse from outside of the appliance, perfect for applications that require replacing the fuse without opening the appliance PPTC DevicesPolySwitch Polymeric Positive Temperature Coefficient (PPTC) devices help protect against damage caused by harmful overcurrent surges and overtemperature faults.

9 Like traditional fuses, these devices limit the flow of dangerously high current during fault conditions. The PolySwitch PPTC device, however, resets after the fault is cleared and power to the circuit is removed, thereby helping to reduce warranty, service and repair costs. PolySwitch PPTC devices are typically used in consumer electronics, automotive, industrial, home appliance, HVAC, and telecommunications DiodesThe Transient Voltage Suppressor diode (TVS Diode) is a protection diode designed to protect electronic circuits from very fast and often damaging voltage transients, such as lightning and Electrostatic Discharge (ESD). TVS Diodes are silicon avalanche devices typically chosen for their fast response time (low clamping voltage), lower capacitance, and low leakage current. TVS Diodes are ideal for applications in computer, industrial, telecom, and automotive Diode ArraysTVS Diode Arrays are designed to protect electronics against transients and overvoltage threats, such as Electrically Fast Transients (EFT) and Electrostatic Discharge (ESD).

10 Because of their lower capacitance and low leakage current, they offer an ideal protection solution for I/O interfaces and digital and analog signal lines, in computer and consumer portable electronics ESD SuppressorsPulseGuard suppressors use polymer composite materials to suppress fast-rising ESD transients while adding virtually no capacitance to the circuit. PulseGuard suppressors are best suited for low-voltage, high-speed applications such as protection for high-speed protocols like USB , IEEE1394, HDMI, and Digital Visual Interface (DVI), where low capacitance is are available in multiple forms, from Metal Oxide Varistors (MOVs) and Thermally Protected MOV (TMOV varistors) that suppress lightning transient voltages to multi -Layer Varistors (MLVs) designed for applications requiring protection from various ESD and EFT transients. They are often used in computers and handheld devices as well as in industrial and automotive Discharge TubesGas Discharge Tubes (GDTs) dissipate voltage transients through a contained plasma gas.