Gas discharge tubes are crucial for safeguarding circuitry against harmful pulses. Littelfuse's SG90 offers an exceptionally compact solution without compromising on power handling capability. With its small form factor, this surface mount gas discharge diode provides efficient protection against damaging surges.

Compact Size with Impressive Performance

Measuring only 4.5 x 3.2 x 2.7 mm, the SG90 is designed to handle high-energy pulses without damage or significant degradation. Littelfuse advertises its ability to divert a 1000A pulse effectively. Furthermore, pulse tests conducted according to IEC 61000-4-5 standards demonstrate a surge capability of 1-2KA with 8/20μS pulses.

Versatility in Voltage Options

The SG series by Littelfuse offers various voltage options, allowing designers to select the ideal part that suits their specific circuit requirements. Proper component selection and simulation are simplified when the gas discharge tube aligns with the maximum voltage seen by subsequent circuit sections. This ensures comprehensive protection within the system.

Wide variety of voltage options

Minimal Signal Interference

Littelfuse has certified the SG90 according to ITU-T K12 and IEC 61000-4-5 standards, commonly utilized in telecommunications. The components exhibit low (less than 1pF) and constant-over-voltage capacitance, making them particularly desirable for shielding ADSL-related circuitry. Additionally, the insertion loss is exceptionally low, reaching a maximum value of 2.1 dB @ 3.5 GHz and an almost negligible 0.01 dB @ 1.0 GHz.

Price Analysis

The SG90 gas discharge tube is widely available from catalog distributors. A search on OEMSecrets reveals that, for quantities of 100, the individual price is approximately 85 euro cents. However, it's important to note that lead times typically range from 16 to 22 weeks.


When high-frequency signal applications require protection from pulses, the Littelfuse SG90 and its gas discharge tube series are highly recommended. Their compact size minimizes the impact on PCB space without compromising on critical circuit protection. With impressive surge capabilities and adherence to industry standards, the SG90 offers an effective solution for ensuring the safety and reliability of electronic systems.