HT32B

Overview

The Littelfuse HT32B is a standard bidirectional DIAC trigger device belonging to the HTxxx, HTMxxx, and STxxx series. It functions as a full-wave semiconductor switch that transitions from a blocking state to a conduction state when the applied voltage amplitude exceeds its breakover threshold in either polarity. The component features a DO-35 glass case package with copper-clad iron leads and matte-tin plating. Electrical specifications include a minimum breakover voltage of 30V and a maximum of 34V at 25°C. It supports a repetitive peak on-state current of 2A for 10µs pulses and operates within a junction temperature range of -40°C to +125°C.

Feature Summary

• Bidirectional triggering capability for symmetrical phase control applications
• Robust construction utilizing epoxy-free glass body material
• High thermal stability with defined derating characteristics above 40°C
• Compliance with lead-free soldering processes and RoHS standards

Applications

• Triac and SCR triggering in lamp dimming circuits
• Universal motor speed control systems
• Solid state ballast lighting controls
• Heat control circuitry

Procurement Notes

Verify the specific ordering suffix against the manufacturer's selector table to confirm the exact package configuration. The HT32B designation corresponds to the DO-35 axial leaded package variant. Confirm availability of bulk or reel pack options based on assembly requirements. Ensure the requested part number matches the required voltage tolerance band of 30V to 34V.

Selection Notes

Select this component for applications requiring precise breakover symmetry and reliable switching in AC phase control environments. Evaluate the thermal resistance parameters to ensure adequate heat dissipation under continuous operation. Consider the physical dimensions of the DO-35 package for PCB layout constraints. Verify that the operating voltage does not exceed the specified breakdown limits during transient conditions.

Part Context

This device is part of the Teccor brand Thyristors portfolio, specifically designed as a bilateral trigger DIAC. It complements other components in the HT series by offering standardized voltage characteristics for industrial and consumer electronics. The product line emphasizes high reliability through rigorous environmental testing protocols including temperature cycling and humidity exposure.

Replacement Considerations

Compatible substitutes within the same family include HT32A and HT34B, provided their respective breakover voltage ranges align with the circuit design requirements. Cross-reference the electrical characteristics and package dimensions to ensure mechanical and functional interchangeability without modifying the existing board layout.