7MBP75RA120-55 Fuji Electric 1200V 75A PIM IGBT Module

Content last revised on November 19, 2025

Fuji Electric 7MBP75RA120-55: A 7-in-1 IPM Engineered for High-Reliability Motor Drives

The Fuji Electric 7MBP75RA120-55 is a highly integrated Intelligent Power Module (IPM) that delivers robust control for three-phase motor drive applications by combining optimized power stages with comprehensive protection features. This module integrates a three-phase IGBT inverter bridge, a brake chopper, and a three-phase diode bridge rectifier into a single compact package. With specifications of 1200V and 75A for the inverter stage, it offers exceptional thermal performance and simplified system design. Key benefits include enhanced reliability through direct junction temperature detection and reduced component count. This IPM directly addresses the engineering challenge of designing compact, efficient, and fault-tolerant variable frequency drives. For systems demanding high reliability and thermal stability in the 15-30 kW power range, the integrated architecture of the 7MBP75RA120-55 provides a distinct advantage.

Application Scenarios & Value

Achieving System-Level Benefits in AC Motor Control and Industrial Inverters

The 7MBP75RA120-55 is engineered specifically for the demanding environment of industrial automation, particularly in Variable Frequency Drives (VFDs) and general-purpose inverters. Its 7-in-1 configuration is a significant asset in these applications. The primary engineering challenge in modern VFD design is maximizing power density and reliability while minimizing assembly complexity and footprint. This module directly solves this by integrating the input rectifier, brake chopper, and output inverter stages. This integration drastically reduces the number of external power components, simplifying PCB layout, reducing potential points of failure, and shrinking the overall size of the drive. The module's ability to directly detect IGBT junction temperature for overheat protection allows for a more precise and rapid response to thermal stress compared to systems relying on external NTC thermistors, preventing catastrophic failures and extending the operational life of the motor drive. While this 75A module is well-suited for a wide range of mid-power motors, for applications requiring slightly less current, the related 7MBP75RA120-50 offers a similar feature set.

Key Parameter Overview

Decoding the Specs for Enhanced Thermal and Electrical Performance

The electrical and thermal characteristics of the 7MBP75RA120-55 are optimized for efficiency and durability in demanding switching environments. The low saturation voltage (VCE(sat)) is a critical parameter, as it directly correlates to conduction losses. A lower VCE(sat) means less power is dissipated as heat during operation, which improves overall system efficiency and eases thermal management requirements. The module's thermal resistance values are equally important, dictating how effectively heat is transferred from the semiconductor junction to the case and, ultimately, to the heatsink.

Download the 7MBP75RA120-55 datasheet for detailed specifications and performance curves.

Frequently Asked Questions (FAQ)

What is the primary benefit of the "7-in-1" integration in the 7MBP75RA120-55?
The core advantage is system simplification. By integrating the three-phase rectifier, brake chopper, and three-phase inverter into one module, it reduces the Bill of Materials (BOM), minimizes PCB space, lowers assembly costs, and enhances reliability by reducing interconnects which can be potential failure points.

How does the integrated overheat protection function?
The module provides a Vot output signal that is proportional to the junction temperature (Tj) of the inverter section's IGBTs. This allows the control circuit to monitor the chip temperature directly and trigger a fault or shutdown before the device reaches its thermal limit, offering a much more accurate and faster protection scheme than relying solely on a case-mounted thermistor.

What does the VCE(sat) of 3.3V (max) at 125°C imply for my design?
This value is critical for calculating conduction power loss (Ploss = VCE(sat) * Ic). A lower VCE(sat) signifies higher efficiency. For a designer, this means less heat is generated for a given current, potentially allowing for a smaller, more cost-effective heatsink or enabling operation at higher ambient temperatures without derating.

Is this module suitable for high-frequency switching applications?
This module is part of Fuji Electric's R-Series IPMs, which are generally optimized for motor drive applications where switching frequencies are typically in the range of 2 kHz to 15 kHz. While it offers soft switching characteristics, for applications requiring significantly higher frequencies, a detailed analysis of switching losses (Eon, Eoff) from the datasheet is necessary to ensure thermal limits are not exceeded.

What is the function of the integrated brake chopper?
The brake chopper is used in motor drive applications to dissipate regenerative energy. When a motor decelerates rapidly, it acts as a generator, sending energy back to the DC bus. The brake chopper switches a resistor across the DC bus to safely dissipate this energy as heat, preventing the DC bus voltage from rising to dangerous levels and protecting the inverter.

Application Vignette

Enhancing Reliability in Conveyor Belt Systems

Consider a variable speed conveyor system in a logistics warehouse, a critical piece of the high-efficiency power systems that keep modern supply chains moving. A frequent engineering challenge is managing the frequent start-stop cycles and sudden load changes, which cause both electrical and thermal stress on the motor drive. An abrupt stop can generate significant regenerative energy, while a heavy load start-up demands high current. The 7MBP75RA120-55 provides a robust, integrated solution. Its built-in brake chopper handles the regenerative energy during deceleration without requiring an external braking unit, simplifying the control cabinet. More importantly, the direct junction temperature sensing provides an unparalleled layer of protection. If a belt jams, causing a prolonged overcurrent condition, the IGBT temperature will rise rapidly. The 7MBP75RA120-55 can signal this overheat condition almost instantaneously to the master controller, allowing for an intelligent shutdown before any permanent damage occurs to the module or the motor. This proactive thermal management is far superior to traditional methods and is key to achieving the long-term operational reliability required in industrial automation.

Technical Deep Dive

A Closer Look at the Integrated Protection and Control Architecture

The "Intelligent" aspect of this Intelligent Power Module (IPM) lies in its built-in control and protection circuits, which offload critical functions from the main system microcontroller and enhance operational security. The 7MBP75RA120-55 incorporates dedicated gate drive circuits optimized for the internal IGBTs, ensuring proper switching characteristics and minimizing oscillations. Crucially, it provides three key protection features: Short Circuit (SC) protection, Under Voltage (UV) lockout, and Over Temperature (OT) protection. The SC protection can detect a phase-to-phase or phase-to-ground fault and safely shut down the IGBTs within microseconds, a timeframe defined by its Short-Circuit Withstand Time. The UV lockout prevents the IGBTs from operating with insufficient gate voltage, which could lead to them operating in the linear region and causing rapid overheating. Think of the UV lockout as a safety check ensuring the IGBTs are "fully told" to be on or off, preventing any ambiguous, high-loss state. The direct junction temperature sensing for OT protection, as previously mentioned, offers the most precise thermal guard. Together, these integrated features create a self-monitoring power stage that simplifies the design of the external control board and provides a robust defense against common failure modes in demanding servo drive and inverter applications.

An Engineer's Perspective on System Integration

From an integration standpoint, the value of the 7MBP75RA120-55 is its ability to consolidate complexity. For engineers designing motor control systems, this module effectively transforms a complex power electronics design challenge into a more manageable system integration task. Instead of sourcing, qualifying, and laying out separate rectifier diodes, braking IGBTs, inverter IGBTs, gate drivers, and protection circuitry, the designer can focus on the control logic and system-level thermal management. This approach not only accelerates the design cycle but also inherently improves reliability by utilizing a pre-validated, optimized subsystem from a single manufacturer. The standardized package and pin-out further streamline manufacturing and serviceability, making it a strategic choice for scalable product platforms where both performance and time-to-market are critical.