MCR12DG

Overview

The Littelfuse MCR12DG is a Silicon Controlled Rectifier (SCR) with a peak repetitive off-state voltage of 400 V. It supports an on-state RMS current of 12 A at 80°C and handles a non-repetitive surge current of 100 A. The device features glass passivated junctions, a maximum forward average gate power of 0.5 W, and operates within a junction temperature range of -40 to +125°C. Electrical characteristics include a gate trigger current maximum of 20 mA, holding current maximum of 40 mA, and a critical rate-of-rise of off-state voltage minimum of 100 V/µs at 125°C.

Feature Summary

• Designed for half-wave AC control applications including motor controls, heating controls, and power supplies.
• Features high immunity to dv/dt with a minimum rating of 100 V/µsec at 125°C.
• Specified with minimum and maximum values for gate trigger current, gate trigger voltage, and holding current to facilitate design flexibility.

Applications

• Half-wave AC control circuits
• Motor controls
• Heating controls
• Power supplies

Procurement Notes

Verify the specific part number suffix against official Littelfuse documentation to confirm voltage ratings and package variations. Ensure that ordering requirements align with the manufacturer's current production status and RoHS compliance declarations. Cross-reference datasheet revision dates to validate parameter accuracy before finalizing procurement specifications.

Selection Notes

Select the MCR12DG when a 400V blocking voltage SCR is required for half-wave applications. Consider thermal resistance values for heat sink sizing in continuous operation. Evaluate gate trigger parameters against driver capabilities to ensure reliable turn-on. Compare surge current ratings against circuit fault conditions to maintain device integrity during transient events.

Part Context

The MCR12DG belongs to the MCR12 series of silicon-controlled rectifiers manufactured by Littelfuse. This series includes variants with different voltage ratings, such as the MCR12MG (600V) and MCR12NG (800V). All devices share the same TO-220AB package and core electrical performance characteristics regarding current handling and switching speeds.

Replacement Considerations

Direct replacements within the same family include the MCR12MG and MCR12NG, which offer higher voltage ratings but maintain identical current and package specifications. Verify that any substitute component meets or exceeds the 400V blocking requirement and matches the TO-220AB footprint for mechanical compatibility.

FAQ

What is the maximum gate trigger current specified for the MCR12DG?

The maximum gate trigger current (IGT) for the MCR12DG is 20 mA under continuous DC conditions with a drain voltage of 12 V and load resistance of 100 Ω.

How does the MCR12DG handle high di/dt conditions?

The device has a repetitive critical rate of rise of on-state current (di/dt) rating of 50 A/µs, tested with a peak current of 50 A and pulse width of 40 µsec.

What is the thermal resistance from junction to ambient for this component?

The thermal resistance from junction to ambient (RθJA) is 62.5 °C/W, while the junction-to-case thermal resistance (RθJC) is 2.2 °C/W.