K1200G

Overview

The Littelfuse K1200G is a silicon bilateral voltage triggered switch (SIDAC) designed for AC circuit protection and triggering applications. It features glass-passivated junctions for ruggedness in harsh environments. The device triggers when the applied voltage exceeds its breakover point, switching to a low on-state voltage until current drops below the holding threshold. Key electrical specifications include a breakover voltage range of 110V to 125V, a repetitive peak off-state voltage of 90V, and an on-state RMS current rating of 1A at 50/60Hz. It supports a peak non-repetitive surge current of 20A for single cycles at 60Hz and operates within a junction temperature range of -40°C to 125°C.

Feature Summary

• Silicon bilateral voltage triggered switch with glass-passivated junctions
• Designed for AC circuit orientation and high-voltage power supplies
• Capable of handling high surge currents for energy dumping

Applications

• High voltage power supplies
• Natural gas igniters
• High-pressure Sodium lamp firing circuits
• Xenon flash ignition systems

Procurement Notes

Verify the specific package type and marking code against the official Littelfuse datasheet before procurement. Confirm that the component meets RoHS compliance requirements if necessary for the target assembly process. Ensure the ordering suffix corresponds to the desired packaging format, such as bulk or reel pack, to match manufacturing line specifications.

Selection Notes

Select the K1200G when a breakover voltage between 110V and 125V is required for triggering or overvoltage protection. Ensure the application current does not exceed the 1A RMS rating under specified thermal conditions. Consider the DO-15 package dimensions and thermal resistance values for proper heat dissipation design in the final enclosure layout.

Part Context

The K1200G belongs to the Littelfuse Kxxxzy series of standard bidirectional SIDACs. This series includes various voltage ratings from 79V to 330V and different package options including DO-15, DO-214, and TO-92. The 'G' suffix specifically denotes the DO-15 axial leaded plastic package, distinguishing it from surface mount or smaller through-hole variants within the same family.

Replacement Considerations

Direct replacements must match the 110V-125V breakover voltage range and DO-15 package. Other manufacturers producing equivalent SIDACs should be evaluated based on identical VBO, IH, and IT(RMS) parameters. Verify that any substitute component offers comparable surge current capability and thermal resistance characteristics.