T107D1

Overview

The Littelfuse T107D1 is a sensitive gate silicon-controlled rectifier (SCR) designed for half-wave unidirectional switching applications. It features a TO-202 package with non-isolated construction and glass-passivated junctions for parameter stability. The device supports a repetitive peak off-state voltage of 400 V and an average on-state current of 2.5 A at 100 °C case temperature, or 4 A at 25 °C. It requires a maximum DC gate trigger current of 500 µA for activation. Key electrical limits include a peak on-state voltage of 2.5 V, a holding current of 8 mA, and a non-repetitive surge current rating of 40 A for one cycle at 60 Hz.

Feature Summary

• Sensitive gate architecture enabling direct interfacing with low-current control logic
• Glass-passivated junctions providing long-term reliability against contamination
• Non-isolated TO-202 leaded package suitable for chassis or wire installation

Applications

• Strobe light triggering circuits
• Fluid level sensing systems
• Capacitive-discharge ignition controls

Procurement Notes

Verify the specific suffix requirements for lead forming configurations before ordering, as standard packages may require modification for certain PCB layouts. Confirm that the non-isolated tab connection aligns with the system's grounding strategy. Ensure the procurement documentation matches the exact Littelfuse part number to avoid confusion with isolated variants or different voltage ratings within the same series.

Selection Notes

Select this component when a 400 V blocking capability and 4 A RMS current handling are required in a standard TO-202 form factor. The 500 µA gate sensitivity allows driving from microprocessors without high-power buffer stages. Consider thermal derating curves if operating near the 110 °C maximum case temperature limit. Verify that the 40 A surge rating meets the peak inrush demands of the specific load circuit.

Part Context

The T107D1 belongs to the Teccor line of sensitive SCRs, which complement Littelfuse's power SCR portfolio. This series covers ratings from 0.8 A to 10 A with voltages up to 600 V. The T107D1 specifically represents the 400 V variant within the 4 A current class, distinguished by its higher gate sensitivity compared to the T106 series.

Replacement Considerations

T106D1 offers identical electrical ratings but with lower gate sensitivity (200 µA max). S4004DS1 provides comparable performance in a TO-251 D-Pak surface mount package.