Part: Littelfuse Gas Discharge Tubes (GDTs)

Type: Gas Discharge Tube (GDT)

Description: Littelfuse Gas Discharge Tubes are crowbar devices designed to protect sensitive telecom and power line equipment from transient surge voltages caused by lightning strikes and switching operations, offering a wide voltage range (75V-4000V), low capacitance, and high surge protection.

Operating Conditions:

• DC Sparkover Voltage Range: 75V to 4000V (@100V/s ± 20% Tolerance)
• Impulse Sparkover Voltage Range: 450V to 5000V (@100V/μs or @1kV/μs)
• Capacitance: <0.5pF to <1.5pF (@1MHz)

Absolute Maximum Ratings:

• Max Impulse Sparkover Voltage: 5000V (@1kV/μs)
• Max Impulse Discharge Current (8x20μs, 10 Hits): 20kA
• Max AC Discharge Current (1s duration; 10 hits): 20Arms (@50 Hz)

Key Specs:

• DC Sparkover Voltage: 75V to 4000V (@100V/s ± 20% Tolerance)
• Impulse Sparkover Voltage: 450V to 5000V (@100V/μs or @1kV/μs)
• Impulse Discharge Current (8x20μs, 10 Hits): Up to 20kA
• Capacitance: <0.5pF to <1.5pF (@1MHz)
• Insulation Resistance: 1,000 MΩ to 10,000 MΩ (@100V DC)
• On-State Voltage: Nominal 20V (@1A)
• DC Holdover Voltage: <52V to <150V (Per ITU K.12)
• AC Discharge Current (1s duration; 10 hits): Up to 20Arms (@50 Hz)

Features:

• RoHS compliant
• Halogen free
• Wide range of voltages (75V-4000V)
• Wide range of form factors (3mm, 5mm, 6mm, 7mm, 8mm diameter devices)
• Low capacitance and insertion loss
• Crowbar device with low arc voltage
• High accuracy spark-over voltages for high precision designs

Applications:

• Telecommunications (MDF modules, xDSL equipment, RF systems, antenna, base stations)
• Industrial and Consumer Electronics (Power supplies, surge protectors, alarm systems, irrigation systems)
• Devices tested per ITU K.12 recommendations
• Devices certified to UL497B and UL1449

Package:

• Surface-mount (3mm, 5mm, 6mm, 8mm diameter)
• Chip GDT (3mm diameter)
• Axial Leads (5mm, 6mm, 8mm diameter)
• No Leads (5mm, 6mm, 8mm diameter)
• T Leaded (5mm diameter)

• RoHS compliant
• Halogen free (refers to: Br ≥ 900ppm, Cl ≥ 900ppm, Br+Cl ≥ 1500ppm)
• Wide range of voltages (75V-4000V)
• Wide range of form factors (3mm, 5mm, 6mm, 7mm, 8mm diameter devices)
• Low capacitance and insertion loss
• Crowbar device with low arc voltage
• High accuracy spark-over voltages for high precision designs

• Telecommunications
• MDF modules, xDSL equipment, RF systems, antenna, base stations
• Industrial and Consumer Electronics
• Power supplies, surge protectors, alarm systems, irrigation systems
• Devices tested per ITU K.12 recommendations
• Various lead configurations and surface-mount options
• Optional fail-short mechanism
• Non radioactive materials
• Devices certified to UL497B and UL1449

GTCX25 Pinout

Package Type: Two-Electrode Gas Discharge Tube (Surface-mount, GTCS25-XXXM-R02 variant)

Notes

• GTCX25 is a two-electrode GDT device with surface-mount (GTCS25-XXXM-R02) configuration.
• The device has only 2 pins/electrodes for surge protection applications.
• Pin numbering follows standard surface-mount pad layout conventions (see Figure G4 pad layout diagram).
• Typical DC sparkover voltage: 75V or 90V (depending on voltage rating variant).
• Impulse sparkover voltage (@1kV/μs): 550V.
• Maximum impulse discharge current: 2.5kA (8×20μs, 10 hits).
• Capacitance: <1pF (suitable for high-frequency applications).
• Insulation resistance: 10,000 MΩ @ 100V DC.
• UL497B certified (#E179610).
• This is a two-electrode device; for three-electrode variants, refer to GTCX35/GTCX36/GTCX37/GTCX38 series.