FUJI 7MBR35U4P120-50 IGBT Module

7MBR35U4P120-50 IGBT Module: Engineering an In-Depth Analysis of Fuji Electric's 1200V 7-Pack

Content last revised on October 14, 2025.

Introduction: A Snapshot of Performance and Integration

Defining Efficiency in a Compact, All-in-One Power Stage

The Fuji Electric 7MBR35U4P120-50 is an integrated power module engineered to optimize efficiency and power density in motor control applications. This module delivers a complete 7-in-1 solution with key specifications of 1200V | 35A, combining a three-phase inverter with a brake chopper circuit. Its primary engineering benefits include significantly reduced conduction losses and a simplified system design. For engineers developing compact servo or variable frequency drives up to ~7.5 kW, this module directly addresses the need for an integrated power stage without compromising on thermal performance. What is the main benefit of its U4-series chip? It achieves a low VCE(sat), directly lowering system heat generation.

Key Parameter Overview

Decoding the Specs for High-Efficiency Motor Drive Design

The technical specifications of the 7MBR35U4P120-50 are foundational to its performance in demanding power conversion systems. The parameters below are grouped by function to provide a clear perspective for design evaluation. The low collector-emitter saturation voltage is a defining characteristic, directly impacting the module's thermal efficiency.

This table presents a selection of key parameters. All design and application decisions must be validated against the official manufacturer's documentation.

Application Scenarios & Value

System-Level Benefits in AC Drives and Servo Systems

Best Fit: For industrial motor drives under 7.5 kW that require regenerative braking capability, the 7MBR35U4P120-50 provides an optimal balance of integration and electrical efficiency. Its all-in-one design is particularly valuable in applications where minimizing footprint and simplifying the assembly process are primary engineering goals.

Consider the design of a compact Variable Frequency Drive (VFD) for a conveyor belt system. The critical challenge is managing both the motive power and the deceleration phase, where the motor acts as a generator. The 7MBR35U4P120-50 directly solves this by integrating the brake chopper, eliminating the need for an external braking unit. This not only reduces the Bill of Materials (BOM) and physical volume but also simplifies the gate drive and control circuitry. The low Vce(sat) of 1.70V translates directly to lower heat dissipation during operation, enabling a smaller heatsink design and improving the overall system's reliability and energy efficiency. While this module is ideal for its current class, for systems demanding higher power output, the related 7MBR50U4P120-50 offers a similar integrated topology with a 50A current rating.

Frequently Asked Questions (FAQ)

What is the primary advantage of the integrated brake chopper in the 7MBR35U4P120-50?
The integrated brake chopper provides a built-in solution for dissipating regenerative energy, which is common in motor applications involving rapid deceleration or overhauling loads. This simplifies the power stage design by removing the need for a separate braking module and its associated wiring and control logic, leading to a more compact, cost-effective, and reliable servo drive system.

How does the U4-Series IGBT technology impact thermal management?
Fuji Electric's U4-Series technology is engineered to minimize conduction losses, evidenced by the low Vce(sat) value. Lower conduction losses mean less energy is converted into waste heat within the IGBT chip for a given current. This directly reduces the thermal load on the module, allowing engineers to design more compact cooling systems or operate at a higher ambient temperature while maintaining a safe junction temperature, thereby enhancing overall system power density and longevity.

Technical Deep Dive

A Closer Look at the U4-Series Chip and 7-in-1 Topology

The performance of the 7MBR35U4P120-50 is rooted in two key design choices by Fuji Electric: the implementation of their 4th generation U-Series IGBT chip technology and the 7-in-1 module configuration. The U4-Series chip represents a refined trade-off between conduction losses (Vce(sat)) and switching losses (Eon/Eoff). For medium-frequency applications like motor drives, where the device spends significant time in the 'on' state, minimizing Vce(sat) is critical for efficiency. Think of Vce(sat) as the 'toll' the current must pay to pass through the switch; a lower toll means more power gets to the motor and less is wasted as heat.

The 7-in-1 topology further enhances its value proposition. By co-packaging the six IGBTs and six Free-Wheeling Diodes (FWDs) for the 3-phase inverter with the seventh IGBT/FWD pair for the brake circuit, the module acts as a nearly complete power stage. This level of integration streamlines manufacturing, reduces parasitic inductance between components compared to a discrete solution, and provides a thermally optimized layout on a single substrate, ensuring more predictable system performance and simplifying compliance with standards like IEC 61800-5-1.

Engineering Support and Next Steps

Accelerating Your Design Cycle with Integrated Solutions

Evaluating the 7MBR35U4P120-50 for your power system requires a thorough analysis of its electrical and thermal characteristics in the context of your specific application load profiles. By integrating key functionalities and optimizing for low conduction losses, this module provides a compelling foundation for developing next-generation, high-efficiency motor control systems. For detailed application notes, thermal modeling data, and to discuss your project's unique requirements, we encourage you to consult the official product documentation and our technical support resources.