S8055R

Overview

The Littelfuse S8055R is a Silicon Controlled Rectifier (SCR) designed for high-power switching applications. It features an 800 V repetitive peak off-state voltage and a 55 A RMS on-state current rating. The device utilizes a TO-220AB flange mount package with three through-hole terminals, where the case is electrically connected to the anode. Key electrical characteristics include a maximum gate trigger current of 40 mA and a forward voltage drop of 1.8 V at rated current. It operates within a junction temperature range of -40 °C to +125 °C and supports non-repetitive surge currents up to 650 A.

Feature Summary

• Robust thermal management via direct flange mounting for efficient heat dissipation in high-current scenarios
• High voltage blocking capability suitable for demanding industrial power control circuits
• Standardized TO-220AB mechanical footprint facilitating integration into existing chassis designs

Applications

• Industrial motor speed control systems
• AC power regulation and soft-start circuits
• Welding equipment power stages

Procurement Notes

Verify the specific suffix designation when ordering, as variations such as S8055R59 or S8055R56 may exist within the product line. Confirm that the required package style matches the TO-220AB flange mount configuration. Ensure compliance with RoHS directives if applicable to the target market. Cross-reference datasheet revisions to confirm parameter stability before finalizing component selection for production.

Selection Notes

Select this component based on its 800 V voltage rating and 55 A continuous current capacity. Evaluate the thermal resistance requirements of the application to determine appropriate heatsinking for the flange mount design. Compare gate trigger specifications against the driving circuit capabilities to ensure reliable turn-on. Consider the physical dimensions of the TO-220AB package for PCB or chassis layout constraints.

Part Context

This SCR belongs to the Littelfuse Teccor series of silicon controlled rectifiers. These devices are engineered for general-purpose power switching tasks. The S8055R variant specifically targets applications requiring moderate to high current handling with robust voltage blocking. It serves as a fundamental building block for thyristor-based power electronics.

Replacement Considerations

Direct replacements must match the 800 V / 55 A specification and TO-220AB flange package. Verify pinout compatibility, particularly the anode-connected case configuration. Check equivalent gate trigger parameters to ensure circuit compatibility without modification.