Gas Discharge Tube Arresters (GDT) are voltage-dependent overvoltage protection devices that utilize ionization of gas to divert high-voltage transients to ground. They act as switches that remain non-conductive under normal operating conditions but rapidly transition to a low-impedance state when voltage exceeds a specific threshold. GDTs play a critical role in safeguarding electronic systems from lightning strikes, electrostatic discharge (ESD), and other transient voltage events in telecommunications, power distribution, and industrial automation systems.
| Type | Functional Characteristics | Application Examples |
| Single-Electrode GDT | Compact design with one gas chamber, suitable for low-energy transients | Consumer electronics, IoT devices |
| Multi-Electrode GDT | Stacked electrodes for higher energy absorption and multi-stage protection | Telecom infrastructure, 5G base stations |
| Inert Gas GDT | Uses argon/neon for stable performance in harsh environments | Industrial control systems, aerospace |
| Metal Vapor GDT | Mercury/xenon vapor for ultra-fast response times | High-speed data lines, medical imaging equipment |
Typical GDT construction includes:
| Parameter | Typical Range | Importance |
| DC Spark-over Voltage | 70V 5kV | Determines trigger threshold |
| Impulse Spark-over Voltage | 100V 10kV | Response under fast transients |
| Max Discharge Current | 10kA 100kA | Overload handling capability |
| Response Time | 0.1 s 1 s | Critical for ESD protection |
| Dielectric Strength | 1kV 20kV/mm | Post-event insulation recovery |
Major industry applications include:
| Manufacturer | Product Series | Key Features |
| Littelfuse | SPA-GDT Series | Hybrid gas-silicon integration, 10kA rating |
| Bourns | 2021 Series | Surface-mount design, 500V breakdown |
| Eaton | Pulsar GDT | 100kA max current, UL94 certified |
| Murata | MA48 Series | Nano-coated ceramic body, -55 C~125 C operation |
Key considerations for GDT selection:
Future development directions: