LD421850

Overview

The LD421850 is a Dual SCR/Diode Isolated POW-R-BLOK module manufactured by Powerex Inc. It features an integrated silicon controlled rectifier and diode within a single isolated package, rated for 1800V repetitive peak forward and reverse blocking voltage and 500A average forward current at 180° conduction with a case temperature of 84°C. The device utilizes compression bonded elements and an aluminum nitride isolator to achieve low thermal impedance. Electrical isolation is provided via a metal baseplate, allowing easy mounting on common heatsinks without additional insulation components. The module operates within a junction temperature range of -40°C to +130°C.

Feature Summary

• Electrically isolated heatsinking capability for simplified thermal management
• Aluminum nitride isolator ensures robust electrical separation between terminals and baseplate
• Compression bonded elements provide reliable mechanical and electrical connections
• UL recognized certification validates safety compliance for industrial applications

Applications

• Bridge circuits requiring phase control
• AC and DC motor drive systems
• Battery supply configurations
• Industrial power supplies
• Large IGBT circuit front ends

Procurement Notes

Verify the complete eight-digit part number LD421850 against official Powerex documentation before procurement. Confirm that the required voltage and current ratings align with specific application demands. Ensure mounting hardware meets the specified torque requirements for M6 and M10 screws. Check for any revision date updates or superseded datasheets to guarantee component authenticity and performance specifications.

Selection Notes

Select this module when phase control and rectification are needed in a compact, isolated form factor. Consider the 1800V rating and 500A current capacity for heavy-duty industrial loads. Evaluate the thermal resistance characteristics to determine appropriate heatsink sizing. Verify compatibility with gate trigger requirements and dV/dt ratings for the specific switching environment.

Part Context

This component belongs to the POW-R-BLOK family of dual SCR/diode isolated modules from Powerex. These modules are designed for high-power applications where electrical isolation and efficient heat dissipation are critical. The series offers various voltage and current combinations to suit different industrial power conversion needs.

Replacement Considerations

Consult Powerex technical support for direct replacements. Verify pinout compatibility and thermal interface dimensions. Ensure equivalent voltage and current ratings are maintained. Check if alternative modules offer improved thermal performance or updated certifications.