What are the main application products of thermistors?

The packaging forms of discharge tubes vary depending on their types (ceramic gas discharge tubes, glass gas discharge tubes, semiconductor discharge tubes) and application scenarios, mainly divided into three categories: surface mount packaging, direct insertion packaging, and axial lead packaging. The following are specific classifications and characteristics:
1、 Ceramic Gas Discharge Tube (GDT) Packaging
Ceramic gas discharge tubes are enclosed in ceramic containers and filled with inert gases such as argon and neon. They have the characteristics of high flow rate (up to 100kA) and high insulation, but their response speed is slow (about 100ns).
Surface mount packaging
Typical sizes: 1206, 1210, 1812 (such as LT-BF/BM/BG series)
Features: Small size, suitable for high-density PCB design, commonly used for power protection of communication equipment.
DIP
Typical models: LT-B5G, LT-B8G (bipolar); LT-B3R, LT-B3D (three poles)
Features: Pin insertion type, good heat dissipation, with a current capacity of over 20kA, commonly used for primary lightning protection of power supplies.
2、 Glass gas discharge tube (SPG) packaging
Glass encapsulated discharge tubes have both high transparency and high temperature resistance, with a response speed better than ceramic tubes (about 80ns), but with a smaller flow rate (≤ 3kA).
Surface mount packaging
Typical dimensions: SMD2643, SMD3167
Application: In low to medium surge protection scenarios, such as consumer electronics signal lines.
DIP
Typical model: DO-41 (axial lead type)
Features: Low cost, easy to manually weld, suitable for power adapters and security equipment.
3、 Semiconductor Discharge Tube (TSS) Packaging
Semiconductor discharge tubes are based on the principle of thyristors, with extremely fast response speed (<1ns), but low current capacity (≤ 400A), making them suitable for fine circuit protection.
Surface mount packaging
Typical model:
SMA/SMB: XXXXMSA/SB series (bidirectional, 6-500V)
SOT23-5: Commonly used for array protection (such as communication interfaces).
DIP
TO-92: PXXX0EA/EB series, suitable for industrial control equipment I/O modules.
Axial lead packaging
DO-41/DO-15: PXXX0LA/LB series, used for telephone lines and modems.
The packaging selection of discharge tubes needs to be comprehensively considered:
Protection level: ceramic tube direct insertion packaging is preferred for high-energy scenarios (such as power lightning protection); Select semiconductor chip packaging for fine circuits (such as data lines).
Space limitations: Surface mount packaging (SMD) is suitable for compact designs, while direct insertion packaging provides better heat dissipation.
Safety requirements: The power input level must be flame retardant packaged with UL/TUV certification (such as ceramic V0 level).
Tip: Glass tubes are easier to observe their internal state due to their transparency, ceramic tubes have higher mechanical strength, and semiconductor tubes excel in response speed.