SJ4040LATP

Overview

The Littelfuse SJ4040LATP is a high-temperature silicon-controlled rectifier (SCR) from the SJxx40x series, designed for robust performance in demanding environments. It features a 400V repetitive peak off-state voltage and a 40A RMS on-state current rating. The device supports junction temperatures up to 150°C, enabling operation with limited cooling capacity or during occasional overloads. Packaged in a TO-220AB through-hole configuration, it offers a low gate trigger voltage of approximately 1.5V and a gate trigger current of 35mA. Key electrical parameters include a non-repetitive peak surge current of 300A, a holding current maximum of 75mA, and a forward voltage drop of 1.6V at rated current.

Feature Summary

• High-temperature capability up to 150°C junction temperature for reliable operation under thermal stress
• Low gate sensitivity requiring minimal control power for triggering
• Robust dv/dt rating to withstand line noise and voltage surges
• TO-220AB package providing flexible mounting options for industrial designs

Applications

• Rectifiers for AC solid state switches
• Industrial motor speed control circuits
• Heating element phase control applications
• Voltage regulator systems

Procurement Notes

Verify the specific suffix LATP against official Littelfuse documentation to confirm pinout orientation and exact thermal characteristics. Ensure the procurement channel provides genuine components with traceable manufacturing data. Cross-reference the part number with the latest datasheet revisions to confirm compliance with current automotive AEC-Q101 standards if required for the target application.

Selection Notes

Select this component when designing circuits that require high current handling in thermally constrained environments. The 150°C rating allows for smaller heat sinks compared to standard 125°C devices. Verify that the gate drive circuit can supply the specified 35mA trigger current. Consider the 300A surge rating for inductive load switching scenarios to ensure adequate safety margins against transient currents.

Part Context

This SCR belongs to the SJxx40x family, Littelfuse's first series rated for 600V/400V, 40Arms, and 150°C junction temperatures. The series addresses thermal runaway risks in applications with limited cooling. The SJ4040LATP specifically utilizes the TO-220AB package, offering a cost-effective through-hole solution for industrial and commercial appliances where surface mount alternatives are not preferred.

Replacement Considerations

Direct replacements within the same series include SJ4040L2ATP, which shares similar electrical ratings but may differ in gate trigger current specifications. Verify package compatibility and thermal resistance values before substituting. Other series such as S4040NRP offer different packaging and current ratings, requiring full circuit re-evaluation.