Tvs Diode Array Spa Diodes Page 2 TVS Diode Array SPA Diodes Catalog

2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 TVS Diode Arrays (SPA Diodes) Introduction to TVS Diode Arrays (SPA Diodes) Littelfuse Silicon Protection Array family of TVS Diode Arrays (SPA Diodes) are designed to protect analog and digital signal lines, such as USB and HDMI, from various transient threats using the lowest possible clamp voltage. They offer broader application use and improved impulse protection performance over conventional diodes. These robust devices safely absorb repetitive ESD strikes at the maximum level (Level 4) specified in the IEC 61000-4-2 international standard, without performance degradation. Key Features Low capacitance 30pF to 0.40pF typically High level of protection: - ESD IEC 61000-4-2: Contact discharge up to 30kV; Air discharge up to 30kV - Lightning, IEC 61000-4-5; Immunity up to 150A - EFT IEC 61000-4-4 40A Low clamping voltage compared to other technologies Up to 14 inputs protection Space saving arrays and ultra-small 0201 and 0402 devices for mounting close to ports for optimal protection RoHS compliant, Lead-Free and Halogen-Free devices How they Work? Littelfuse TVS Diode Array devices provide high level protection against Electrostatic Discharge (ESD), Electromagnetic Interference (EMI) and Lightning, mainly for sensitive digital and analogue input circuits, on data, signal, or control lines operating on power supplies. These devices work in two ways. First, they absorb transients with diodes, to steer the current, and then, an avalanching or zener diode, clamps the voltage levels. This prevents the device from exceeding its voltage rating. During over-voltage fault conditions, the device must have a low clamp voltage at the specified current wave form to protect sensitive IC's and ports. In normal operation, the reverse stand off voltage must be higher than the equipment supply/working voltage, with low leakage current to prevent power supply loading. The device capacitance must be low enough to reduce input signal distortion. The device package must have a small footprint and low height to enable a high density Printed Circuit Board (PCB) layout. The device must withstand multiple ESD pulses as specified in the IEC 61000-4-2. Data Protocols and End Applications The diagrams on the next page show the relationship between Data Rates (Protocol), Applications, and Littelfuse TVS Diode Arrays (SPA Diodes). The top diagram shows the standard data protocols, associated data rates, example end applications, and applicable Littelfuse SPxxxx device series. Similarly, the bottom diagram shows common end applications and applicable SPxxxx devices in table format. This information, along with the example circuit protection configuration diagrams on the following pages, and within each data sheet, is intended to help circuit designers determine which Littelfuse suppressors are most appropriate for the situation. Most electronic products today use several port and data protocol types, and so require multple strategies of protection at each possible ESD transient entry point. Concern About Capacitance As data rate and data integrity concerns increase, so should concern about the capacitance of the suppression device. For example, audio and mouse ports on most PCs use relatively slow data rates where capacitance of the ESD protector is not very important. However, in today's higher bandwidth applications, the designer must be very conscientious about the parasitic capacitance of the protection device, to ensure that it does not cause signal degradation at very high frequencies. As data rates have continued to push higher (e.g. USB3.0, Gigabit Ethernet, HDMI, etc) chipsets have become more sensitive to ESD and other electrical transients by virtue of their small geometry processing. The only technology currently capable of preserving signal integrity and providing very low clamping voltages are Littelfuse SPA Diodes. Other key characteristics such as leakage current, number of lines of protection, ESD immunity, and footprint also need to be considered, especially where there are overlaps in the recommended Littelfuse ESD suppressor line. If you require further assistance in selecting the appropriate Littelfuse ESD suppressor for your specific circuit, please contact your local Littelfuse products representative. TVS Diode Array Technology and Applications Overview

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