ST32B

Overview

The Littelfuse ST32B is a standard bidirectional DIAC trigger device belonging to the HTxxx, HTMxxx, and STxxx series. It is designed for triggering Triacs and SCRs in phase control circuits. The component operates within a breakover voltage range of 30V (minimum) to 34V (maximum). It utilizes a DO-214 surface-mount package with high-quality junctions and white wave soldered die attachment. The device supports a pulse on-state current of 2A at 120 pulses per second and maintains an operating junction temperature range from -40°C to +125°C.

Feature Summary

• Bidirectional switching capability for either polarity of applied voltage
• High-quality junctions with white wave soldered die attachment
• RoHS compliant construction with lead-free termination finish

Applications

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

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact package type and packaging format. Ensure that any requested variations align with the published part numbering system to avoid receiving incorrect physical configurations or reel specifications.

Selection Notes

Select this component based on the required breakover voltage symmetry and the specific thermal dissipation needs of the application. Consider the DO-214 package dimensions and the maximum power dissipation limits when designing the printed circuit board layout to ensure reliable operation under varying ambient temperatures.

Part Context

This device is part of the broader HTxxx, HTMxxx, and STxxx family of standard bidirectional DIAC triggers manufactured by Littelfuse. These components are engineered to provide consistent triggering characteristics for various thyristor-based control applications across different industrial and consumer electronics sectors.

Replacement Considerations

Compatible substitutes within the same series include the HT-32B and HTM-32B variants. Verify that replacement parts match the original DO-214 package footprint and maintain identical electrical breakover voltage parameters to ensure circuit compatibility.

FAQ

What is the breakover voltage range for the ST32B?

The breakover voltage ranges from a minimum of 30V to a maximum of 34V.

What package style does the ST32B utilize?

The ST32B utilizes the DO-214 surface-mount package.

How does the ST32B handle voltage polarity?

It is a bidirectional device triggered from a blocking state to a conduction state for either polarity of applied voltage.