MCR72-8TG

Overview

The Littelfuse MCR72-8TG is an 8 Amp Silicon-Controlled Rectifier (SCR) housed in a TO-220AB package. It features a peak repetitive off-state voltage of 600V and supports an on-state RMS current of 8.0A at 180-degree conduction angles. The device handles a peak non-repetitive surge current of 100A with an I²t rating of 40 A²s. Electrical characteristics include a maximum gate trigger current of 200 µA, a peak forward on-state voltage of 2.0V, and a holding current of 6.0mA. Thermal resistance from junction to case is 2.2°C/W, allowing operation within a junction temperature range of -40°C to +110°C.

Feature Summary

• Center gate geometry ensures uniform current density across the silicon structure.
• All diffused and glass-passivated junctions provide parameter stability and durability.
• Thermowatt construction offers low thermal resistance for high heat dissipation.
• Low trigger currents allow direct interfacing with integrated circuits.

Applications

• Temperature control systems
• Light dimming and speed control circuits
• Process and remote controls
• Capacitive discharge ignition circuits

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation before procurement. Confirm that the component meets RoHS compliance requirements if necessary for your assembly process. Ensure proper mounting torque specifications are followed during installation to maintain thermal performance and mechanical integrity.

Selection Notes

Select this component when a robust 600V blocking capability is required alongside an 8A continuous load capacity. The low gate trigger current makes it suitable for microprocessor-driven applications where minimal drive power is available. Evaluate the thermal management strategy based on the specified junction-to-case thermal resistance for your operating environment.

Part Context

This part belongs to the MCR72 series of thyristors designed for industrial and consumer electronics. The series includes variants with different voltage ratings, such as the MCR72-3 and MCR72-6, sharing similar current handling and physical packaging characteristics. The 'T' designation typically indicates tape and reel packaging, while 'G' denotes lead-free construction.

Replacement Considerations

Direct replacements must match the 600V blocking voltage, 8A RMS current, and TO-220AB package dimensions. Verify that alternative SCRs possess comparable gate trigger characteristics and thermal resistance values to ensure circuit compatibility without redesigning the driver stage or heatsink.

FAQ

What is the maximum gate trigger current for the MCR72-8TG?

The maximum gate trigger current (IGT) is 200 µA under continuous DC conditions with a 12V supply and 100 Ω load.

How does the center gate geometry benefit this SCR?

The center gate geometry ensures uniform current density distribution across the device, enhancing reliability and parameter stability.

What is the critical rate-of-rise of off-state voltage (dv/dt)?

The critical rate-of-rise of off-state voltage is 10 V/µs at a junction temperature of 110°C with the gate open.