TVS Diode for USB Data Line ESD Protection

Question

Problem: TVS Diode for USB Data Line ESD Protection. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

Every time a user plugs a USB cable, static discharge from their body can reach thousands of volts in nanoseconds. This ESD strike travels directly into the MCU’s USB data pins, which are rated for only ~4V absolute maximum.

A bidirectional TVS diode on each data line clamps ESD strikes to a safe voltage (~17V peak for nanosecond pulses — MCU pins can survive these brief transients). Critical: the TVS must have very low capacitance (≤5pF) to avoid distorting fast USB data signals.

Required: Bidirectional · Vstandoff 5–6.5V · Vclamp ≤17V · ≥40W · ≤5pF · SOD-882 · Littelfuse

2. How to Find It on DigiKey

Go to DigiKey.com → Circuit Protection → TVS - TVS Diodes

Apply these filters:

Bidirectional Channels → 1
Voltage - Reverse Standoff (Typ) → 5V to 6.5V range
Voltage - Clamping (Max) → 17V or lower
Capacitance → 5pF or lower
Package / Case → SOD-882
Manufacturer → Littelfuse Inc.
Part Status → Active

Important: Capacitance is critical for USB. A TVS with 50pF capacitance would corrupt USB Full-Speed and Hi-Speed data. Always verify ≤5pF for data line TVS protection.

3. Key Specifications & What They Mean

Specification	Required	Why
Direction	Bidirectional	ESD can strike in both polarities.
Standoff Voltage	5–6.5V	Above USB 5V VBUS; no interference.
Clamping Voltage	≤17V	Brief ESD pulse within MCU survival range.
Peak Pulse Power	≥40W	Handles ESD energy.
Capacitance	≤5pF	Preserves USB signal integrity.
Package	SOD-882	Compact; fits near USB connector.
Manufacturer	Littelfuse	Company AVL requirement.
RoHS	Yes	Compliance required.

4. Selecting a Safe, Production-Ready Part

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

5. Filtered DigiKey Link

➡ View Matching Parts — Littelfuse, Bidirectional TVS, 5–6.5V, ≤5pF, SOD-882

28. TVS Diode for USB Data Line ESD Protection