CST306-3A-B

Overview

The Triad Magnetics CST306-3A-B is a through-hole current sense transformer designed for board mounting. It features a 50:1 turns ratio and an inductance of 3.75 mH (max). The device supports a maximum primary current of 25 A and operates within a frequency range of 20 kHz to 200 kHz. Secondary resistance is specified at 340 mohms. Physical dimensions include a length of 17.53 mm, width of 9.78 mm, and height of 23.24 mm.

Feature Summary

• Provides electrical isolation between primary circuit and secondary sensing electronics
• Encapsulated toroidal core construction for environmental protection
• Radial lead termination facilitates standard through-hole PCB assembly

Applications

• Switch-mode power supply current monitoring
• Inverter and motor drive overcurrent protection
• Industrial power converter feedback loops

Procurement Notes

Verify the specific suffix 'B' against manufacturer documentation to confirm packaging configuration, as designators may indicate bulk or tape-and-reel formats. Ensure the selected component matches the required 25 A rating and 20-200 kHz operational bandwidth for the target application. Cross-reference the datasheet for precise mechanical tolerances before finalizing the PCB footprint.

Selection Notes

Select this component when a 50:1 step-down ratio is required for current sensing applications. The 25 A primary rating suits moderate-power industrial systems. Verify that the 340 mohm secondary resistance aligns with the input impedance requirements of the downstream amplifier or ADC. Confirm that the 20 kHz lower frequency limit does not interfere with low-frequency signal integrity needs.

Part Context

This part belongs to the CST306 series of current sense transformers from Triad Magnetics. The series offers various ratios and current ratings for different power levels. The CST306-3A-B variant specifically targets 25 A applications with encapsulated construction for durability in industrial environments.

Replacement Considerations

Direct substitutes include the CST306-3A and CST306-1A. Verify that alternative models match the 50:1 ratio and 25 A current rating. Check physical dimensions to ensure compatibility with existing PCB layouts.