HT32

Overview

The Littelfuse HT32 is a standard bidirectional DIAC trigger device belonging to the Teccor brand Thyristors family. It operates within a breakover voltage range of 27V (minimum) to 37V (maximum). The component transitions from a blocking state to a conduction state when the applied voltage amplitude exceeds its breakover threshold, functioning for either polarity of applied voltage. It supports a pulse on-state current of 2A at 120 pulses per second with a 10μs width and maintains an operating junction temperature range from -40°C to +125°C.

Feature Summary

• Bidirectional triggering capability for full-wave phase control applications
• Robust construction utilizing glass case body materials
• Lead-free soldering compatibility with matte-tin plated terminals

Applications

• Lamp dimming circuits
• Universal motor speed control systems
• Heat control mechanisms
• Solid state ballast lighting controls

Procurement Notes

Verify the specific package configuration required for your assembly process, as the HT32 designation corresponds to the DO-35 leaded variant. Confirm that the ordering suffix matches your preferred packing mode, distinguishing between bulk packaging and tape-and-reel formats. Ensure the selected part number aligns with the exact breakover voltage tolerance specifications needed for your circuit design before finalizing procurement orders.

Selection Notes

Select the HT32 based on the required breakover voltage symmetry and the physical constraints of the printed circuit board layout. Evaluate the thermal resistance characteristics relative to the ambient operating conditions to ensure reliable performance. Consider the available package options, such as DO-35 or surface mount variants, to determine the most suitable form factor for integration into the target electronic system architecture.

Part Context

The HT32 is part of the broader HTxxx, HTMxxx, and STxxx series of bilateral trigger DIACs manufactured by Littelfuse. This series provides a comprehensive range of voltage characteristics spanning from 27V to 70V. These devices are engineered to serve as reliable gate triggers for Triacs and SCRs in various power control scenarios, ensuring consistent switching behavior across different environmental conditions.

Replacement Considerations

Compatible substitutes include the HTM-32B and ST-32B, which offer identical electrical characteristics but utilize MINIMELF and DO-214 packages respectively. When replacing the HT32, verify that the alternative package type fits the existing footprint or allows for necessary PCB modifications without compromising electrical performance or mechanical stability.