--- title: "How to protect electronics from ESD: guidance for USB-C, USB4, and Ethernet designs" description: "How to protect electronics from ESD: guidance for USB-C, USB4, and Ethernet designs, choosing ESD diodes, and preventing circuit damage in modern systems." image: https://solutions.mccsemi.com/hubfs/ESD%20Protection%20how%20to%20design%20robust%20ESD%20%20mcc%20semi.%20micro%20commercial%20components-1.png --- [![MCC Logo](https://solutions.mccsemi.com/hs-fs/hubfs/brand-assets/Logo/MCC%20Logo%201x.png?width=100&height=43&name=MCC%20Logo%201x.png) ![Micro Commercial Components](https://solutions.mccsemi.com/hs-fs/hubfs/brand-assets/Logo/MCC%20Logo%201x.png?width=140&height=60&name=MCC%20Logo%201x.png)](https://www.mccsemi.com/) [Get Started](https://www.mccsemi.com/Contact/Index) # ESD Protection: How to Design Robust ESD, Surge, and Overvoltage Protection for Modern Electronics ## Practical guidance for engineers designing USB-C, Ethernet, automotive, industrial, and high-speed interfaces - Topics Covered in this Guide ## How to Protect Electronics from ESD Electrostatic discharge (ESD) is one of the leading causes of electronic system failure. As devices integrate USB PD up to 48 V, USB4 high-speed differential pairs, Automotive Ethernet, and increasingly compact connectors, designing ESD protection early is essential to meeting reliability and compliance requirements. This page explains what ESD protection is, how to design ESD protection, what kind of diode is used for ESD protection, and how to protect circuits and electronics from ESD across USB-C, Ethernet, video, and other high-speed interfaces. It also provides guidance for selecting MCC ESD protection diodes, TVS diodes, and overvoltage protection (OVP) devices. ## What Is ESD Protection and Why It Matters ESD protection refers to the design practices and components, primarily ESD protection diodes, TVS diodes, and OVP devices that prevent electrostatic discharge from damaging sensitive electronics. Real-world ESD events can exceed tens of thousands of volts with sub-nanosecond rise times. Without proper protection, ESD and electrical overstress (EOS) can cause: - IC and transceiver damage - USB port failures - Ethernet PHY failures - Latch-up events - Long-term reliability problems There are several models developed to simulate an ESD event. Below table shows the industrial standards: | **ESD model** | **Application level** | **Simulated event** | **Test conditions** | **Peak voltage** | **Peak current** | **Stored energy** | | --- | --- | --- | --- | --- | --- | --- | | HBM (JS-001) | Component level | A person who has built up static charge (e.g., by walking on a carpet) and then discharges that energy directly through their finger when touching an electronic device | 100 pF / 1.5 kΩ Tr = 2–10 ns Td = ~150–200 ns | Up to 8 kV | ~5.3 A (at 8 kV) | 3.2 mJ | | CDM (JS-002) | Component level | A scenario where the device itself becomes charged (e.g., sliding down a production line) and then discharges all its stored energy instantly when one of its pins touches a grounded surface | Device‑dependent\* / \< 1 Ω Tr = 0.1–0.5 ns Td = ~1–8 ns | Up to 1 kV (or higher) | 5–20 A (at 500 V) | ~2 µJ (for 4 pF at 1 kV) | | IEC 61000-4-2 | System level | A more energetic event where a charged person, often holding a metal tool like a key or screwdriver, discharges directly into a finished, operational electronic product | 150 pF / 330 Ω Tr = 0.7–1 ns Td = ~60–100 ns | Up to 30 kV (air) | ~30 A (at 30 kV) | 67.5 mJ | | ISO 10605 | Automotive system level | A discharge from a charged metal object (like a repair tool, fuel nozzle, or a car's metal door frame) to an electronic module inside a vehicle | 330 pF / 330 Ω Tr = 0.7–1 ns Td = ~50–100 ns | Up to 30 kV | ~112.5 A (at 30 kV)\*\* | 148.5 mJ (at 30 kV) |   | ![ESD Waveform comparison 0-200ns mcc semi-1](https://solutions.mccsemi.com/hs-fs/hubfs/ESD%20Waveform%20comparison%200-200ns%20%20mcc%20semi-1.png?width=500&height=300&name=ESD%20Waveform%20comparison%200-200ns%20%20mcc%20semi-1.png)   | ![Initial ESD Waveform comparison 0-30ns - mcc semi-1](https://solutions.mccsemi.com/hs-fs/hubfs/Initial%20ESD%20Waveform%20comparison%200-30ns%20-%20mcc%20semi-1.png?width=500&height=300&name=Initial%20ESD%20Waveform%20comparison%200-30ns%20-%20mcc%20semi-1.png)   | | --- | --- | | ESD Waveform Comparison (0-200ns) @30kV Max Stress | Initial ESD Waveform Comparison (0-30ns) @30kV |   Internal IC protection is designed only for device-level HBM and CDM handling events and cannot withstand IEC 61000-4-2 system-level ESD exposure through external connectors. External ESD and TVS protection devices are required at every exposed interface. ## How ESD Damages Electronics To design ESD protection effectively, engineers must understand the underlying failure mechanisms. **1. Direct Overvoltage Stress** - Voltage spikes exceed breakdown limits of semiconductor structures. **2. High Transient Current** - Fast current pulses damage internal metal layers and I/O protection cells. **3. Capacitive and Inductive Coupling** - ESD energy can couple into high-speed lines without direct contact. **4. Connector Injection Points** - USB-C, RJ45, HDMI, and DisplayPort connectors are common paths for ESD energy to enter a system. **5. Real-World Failures** - Damaged ports - PHY failures - Signal degradation - Intermittent or latent failures that may pass production testing but fail later in the field ## How to Design ESD Protection **1. Identify All ESD Entry Points** Common exposure points include: - USB-C ports - Ethernet jacks - HDMI, DisplayPort, and LVDS connectors - LEDs, buttons, and open-drain outputs - Sensor interfaces - Test pads and housings **2. Choose the Correct Protection Devices (ESD Diodes and TVS Diodes)** Both ESD protection diodes and TVS diodes are commonly used to address different transient threats within the same system. **ESD Protection Diodes** - Ultra-low capacitance - Ultra-fast response - Optimized for high-speed interfaces such as USB4, HDMI, DP, DisplayPort, and Ethernet **TVS Diodes** - Handle larger surge energy - Protect power rails such as VBUS and automotive supply lines - Complement ESD diodes in mixed-transient environments In practice, ESD diodes are selected primarily for speed and capacitance, while TVS diodes are selected for energy handling and voltage rating. Learn more about selecting between TVS and ESD devices here: [Understanding TVS Diodes – A Comprehensive Guide](https://solutions.mccsemi.com/understanding-tvs-diodes-a-comprehensive-guide?hsLang=en) **3. Match the Device to the Interface** High-Speed data lines, control signals, and power rails require different protection strategies. The table below outlines which protection devices are best suited for each common interface. | **Interface** | **Recommended Device** | | --- | --- | | USB4 and USB3.x  | Ultra-low capacitance ESD diodes below 0.3 pF | | USB-C CC and SBU | Overvoltage protection devices | | USB PD VBUS 5 to 48 V | High-Ipp TVS diodes | | Automotive Ethernet | Low-capacitance ESD diodes meeting OPEN Alliance requirements | | 1 to 10 GbE | Ultra-low capacitance ESD diodes between 0.15 and 0.25 pF | | HDMI, DP, LVDS | Ultra-low capacitance ESD diodes below 0.20 pF | | Open-drain outputs | Unidirectional ESD diodes | | LEDs | Small-signal ESD diodes |   **4. Follow ESD PCB Layout Best Practices** Correct PCB layout ensures ESD energy is safely diverted away from sensitive components. Without proper placement and routing, ESD protection devices cannot function effectively. - Place ESD devices as close as possible to the connector - Minimize inductance by keeping traces short - Maintain symmetry on differential pairs - Provide a low-impedance ground path - Avoid routing ESD discharge currents near sensitive circuitry **5. Validate Using System-Level Tests** System-level validation ensures that ESD and surge protection strategies remain effective beyond the schematic. Testing verifies immunity, compliance, and long-term reliability. - IEC 61000-4-2 ESD - IEC 61000-4-4 EFT - IEC 61000-4-5 surge - USB and Ethernet compliance - Automotive EMC tests       ## USB ESD Protection for USB-C, USB 3.x, and USB4 [![Next-Gen USB ESD Protection\_ Tailored Solutions from MCC](https://solutions.mccsemi.com/hs-fs/hubfs/Next-Gen%20USB%20ESD%20Protection_%20Tailored%20Solutions%20from%20MCC.png?width=1080&height=400&name=Next-Gen%20USB%20ESD%20Protection_%20Tailored%20Solutions%20from%20MCC.png)](https://solutions.mccsemi.com/news/next-gen-usb-esd-protection-tailored-solutions-from-mcc?hsLang=en) USB-C combines high-voltage power delivery, sensitive control signals, and multi-gigabit data channels within a compact connector. This combination makes USB interfaces especially vulnerable to ESD, electrical overstress, and hot-plug events, particularly when CC and SBU pins are exposed to transient shorts with VBUS during insertion or removal. Effective USB ESD protection requires a coordinated approach that includes overvoltage protection for CC and SBU pins, high-current TVS diodes for VBUS rails up to 48 V, and ultra-low-capacitance ESD diodes for USB 3.x and USB4 differential pairs to preserve signal integrity. A detailed design guide with device recommendations, placement strategies, and automotive considerations is available here: [Next-Gen USB ESD Protection: Tailored Solutions from MCC](https://solutions.mccsemi.com/news/next-gen-usb-esd-protection-tailored-solutions-from-mcc?hsLang=en) ## Ethernet ESD Protection from 100BASE-T1 to 10GbE [![Ultimate Ethernet ESD Protection\_ High-Performance Devices from MCC](https://solutions.mccsemi.com/hs-fs/hubfs/Ultimate%20Ethernet%20ESD%20Protection_%20High-Performance%20Devices%20from%20MCC.png?width=1080&height=400&name=Ultimate%20Ethernet%20ESD%20Protection_%20High-Performance%20Devices%20from%20MCC.png)](https://solutions.mccsemi.com/news/ultimate-ethernet-esd-protection-high-performance-devices-from-mcc?hsLang=en) Ethernet interfaces are highly sensitive to ESD because even small parasitic capacitances can degrade differential signaling, especially at gigabit and multi-gigabit speeds. ESD can enter through RJ45 connectors, cable shields, or LED control pins and propagate toward the PHY if not properly suppressed. Robust Ethernet ESD protection focuses on ultra-low-capacitance ESD diodes placed on the secondary side near the PHY, with strategies that balance immunity against IEC 61000-4-2 requirements while maintaining return loss and insertion loss performance. Automotive Ethernet adds further challenges, requiring compliance with OPEN Alliance EMC guidelines and resilience to higher discharge levels. Recommended protection approaches and device examples are covered in detail here: [Ultimate Ethernet ESD Protection: High-Performance Devices from MCC](https://solutions.mccsemi.com/news/ultimate-ethernet-esd-protection-high-performance-devices-from-mcc?hsLang=en) ## Video and Display ESD Protection for HDMI, DisplayPort, and LVDS [![Next-Gen Video ESD Protection\_ High-Performance Solutions from MCC](https://solutions.mccsemi.com/hs-fs/hubfs/Next-Gen%20Video%20ESD%20Protection_%20High-Performance%20Solutions%20from%20MCC.png?width=1080&height=400&name=Next-Gen%20Video%20ESD%20Protection_%20High-Performance%20Solutions%20from%20MCC.png)](https://solutions.mccsemi.com/news/next-gen-video-esd-protection-high-performance-solutions-from-mcc?hsLang=en) High-speed video and display interfaces operate with extremely tight signal integrity margins, making them some of the most ESD-sensitive connections in modern electronics. Even minimal capacitance or asymmetry introduced by protection components can distort eye diagrams and reduce link reliability. ESD protection for video interfaces requires ultra-low-capacitance ESD diodes placed directly at the connector, with careful attention to symmetrical loading across differential pairs. These devices must provide fast clamping for connector discharge events while remaining electrically transparent at high data rates. Design considerations and optimized solutions for video and display interfaces are explored here: [Next-Gen Video ESD Protection: High-Performance Solutions from MCC](https://solutions.mccsemi.com/news/next-gen-video-esd-protection-high-performance-solutions-from-mcc?hsLang=en) Explore MCC [ESD](https://www.mccsemi.com/products/protection-devices/esd-protection-devices) and [TVS](https://www.mccsemi.com/products/protection-devices/tvs) protection devices for high-speed, power, and automotive applications.   --- ## Contact MCC for advanced solutions that deliver a competitive edge. Contact our team for personalized support and advanced solutions designed to provide you with a competitive edge in your industry. MCC is a manufacturer of high-quality discrete semiconductors to the consumer markets © MCC. All Rights Reserved · 2026