Content last revised on November 20, 2025
PM15RSH120: Engineering Analysis of a 1200V / 15A Intelligent Power Module
M2. Introduction & Core Highlights
Accelerating Development of Compact, High-Reliability Motor Drives
The Mitsubishi PM15RSH120 is an Intelligent Power Module (IPM) engineered to streamline the design of compact and robust three-phase motor control systems. Its core value lies in the high level of integration, combining a 1200V/15A IGBT inverter stage with optimized gate drive circuitry and a comprehensive suite of protection functions within a single, isolated package. This integration directly addresses the engineering challenge of minimizing design complexity and enhancing operational reliability. Key specifications include: 1200V VCES | 15A IC | Integrated Over-Current, Short-Circuit, and Over-Temperature Protection. The primary benefits are a significantly reduced design cycle and superior system-level dependability. For low-horsepower motor drives requiring minimal footprint and maximum uptime, the PM15RSH120's built-in intelligence provides an optimal balance of performance and protection.
B3. Key Parameter Overview
Specifications Translated to System-Level Value
The technical specifications of the PM15RSH120 are not just numbers; they represent tangible engineering advantages. The following table highlights key parameters and interprets their direct impact on application performance and design considerations. This approach moves beyond raw data to facilitate a more informed component evaluation process.
| Parameter | Value | Engineering Significance & Value |
|---|---|---|
| Collector-Emitter Voltage (VCES) | 1200V | Design Margin for 400V/480V AC Lines: Provides substantial voltage headroom for industrial motor drives operating on three-phase 400V or 480V systems, ensuring reliable performance even with line voltage fluctuations and transient overvoltages. |
| Collector Current (IC) | 15A (TC = 25°C) | Sufficient Power for Low-HP Motors: Comfortably drives fractional to low horsepower AC induction or brushless DC motors, making it suitable for applications like conveyor systems, pumps, and automated machinery. |
| Integrated Protections | Short-Circuit (SC), Over-Current (OC), Over-Temperature (OT), Under-Voltage (UV) | Enhanced System Robustness: This is the module's core value. Integrating these functions eliminates the need for complex external protection circuits, reducing component count, minimizing PCB space, and critically, providing fast, coordinated protection that prevents catastrophic IGBT failure. |
| Isolation Voltage (Viso) | 2500 Vrms (AC, 1 min) | Simplified Safety & Compliance: Ensures high dielectric strength between the power terminals and the mounting baseplate. This simplifies meeting safety standards like UL and IEC by providing reliable electrical isolation from the heatsink and chassis. |
| Internal NTC Thermistor | Yes | Real-Time Thermal Feedback: The inclusion of a Negative Temperature Coefficient thermistor allows the system controller to monitor the module's internal temperature directly. This enables precise thermal management, allowing for over-temperature warnings or controlled shutdowns before damage can occur. |
Download the PM15RSH120 datasheet for detailed specifications and performance curves.
B2. Application Scenarios & Value
System-Level Benefits in Automated Machinery and HVAC Systems
The true value of the PM15RSH120 Intelligent Power Module (IPM) is realized in applications where reliability, compact design, and reduced time-to-market are critical engineering goals. Its integrated nature makes it an excellent fit for decentralized or cabinet-integrated motor drives. For systems that require higher power handling, the related PM100CSD120 offers a higher current rating within a similar functional family.
Consider the engineering challenge of designing a compact servo drive for a multi-axis CNC machine. Board space is at a premium, and the drive must be immune to the electrical noise common in such environments. A discrete solution, involving separate IGBTs, gate drivers, and protection circuitry, would be larger, more complex, and susceptible to noise-induced faults. The PM15RSH120 solves this by co-packaging the power and control stages. The optimized internal layout and short signal paths between the gate driver and IGBTs minimize parasitic inductance, leading to cleaner switching and improved noise immunity. Furthermore, its built-in short-circuit protection is indispensable in a servo application, where a motor stall could create a destructive short-circuit condition. The IPM's ability to detect and safely shut down within microseconds is a critical feature that a discrete implementation struggles to match in speed and reliability.
B1. Technical Deep Dive
A Closer Look at the "Intelligent" in IPM for Design Simplification
The designation "Intelligent Power Module" directly refers to the integration of control and protection circuits alongside the power switching IGBTs. The PM15RSH120 architecture includes a three-phase IGBT inverter bridge and a brake chopper, all driven by dedicated high-voltage ICs (HVICs) and low-voltage ICs (LVICs) within the same housing. This integration provides several profound engineering advantages over traditional discrete component designs.
First, the gate drive circuit is factory-optimized for the specific IGBTs it controls. This eliminates a significant design burden for the engineer, who would otherwise need to perform complex calculations and component selection for gate resistors, Zener clamps, and bootstrap circuits to ensure proper switching speed while managing overshoot and ringing. The optimized drive guarantees efficient switching performance and minimizes the risk of parasitic turn-on. Second, the protection logic for over-current, short-circuit, and under-voltage is built-in. This is analogous to having a dedicated watchdog circuit for the power stage. It continuously monitors the IGBTs' status and provides a simple fault signal to the system's microcontroller, allowing for a swift and graceful shutdown in the event of an anomaly. This level of coordinated, high-speed protection is extremely challenging and costly to replicate with external sense resistors, comparators, and logic gates, making the IPM a more robust and reliable solution from the outset.
B7. FAQ
Engineering Questions on the PM15RSH120
What is the primary benefit of using an IPM like the PM15RSH120 over discrete IGBTs and a separate gate driver?
The primary benefit is design simplification and enhanced reliability. The IPM integrates an optimized gate driver and a suite of protection features, which reduces PCB complexity, component count, and development time. This integration also minimizes parasitic inductance, leading to better switching performance and higher system robustness.
How does the integrated under-voltage (UV) protection work and why is it important?
The under-voltage lockout ensures that the internal gate drive circuitry has sufficient supply voltage to fully turn on the IGBTs. If the control voltage drops, the IGBTs might operate in the linear region, leading to excessive power dissipation and potential failure. The UV protection circuit prevents this by disabling the gate drive and issuing a fault signal until the supply voltage is restored to a safe level.
What is the function of the integrated brake chopper circuit?
The brake chopper provides a path to dissipate regenerative energy from a decelerating motor. When a motor acts as a generator, it sends current back to the DC bus, causing its voltage to rise. The brake chopper switches a resistor across the DC bus to dissipate this excess energy as heat, preventing the bus voltage from reaching damaging levels.
Can the fault output (FO) pin distinguish between different types of faults?
Typically, the fault output pin on an IPM like this is a common alarm signal. It indicates that one of the protection features (over-current, short-circuit, or over-temperature) has been triggered. The system's microcontroller should then initiate a shutdown procedure. Differentiating the exact fault type often requires additional external circuitry or may be detailed in the manufacturer's specific application notes.
How does the built-in NTC thermistor improve system reliability?
The NTC thermistor provides a real-time analog feedback of the module's internal substrate temperature. This allows the system controller to implement a proactive thermal management strategy. For example, it can throttle down motor current or increase cooling fan speed as the temperature rises, preventing a hard shutdown and improving the overall operational availability and lifespan of the drive. For more on the importance of thermal performance, see this guide on unlocking IGBT thermal performance.
Next Steps for Your Design
To further evaluate the PM15RSH120 for your specific application, we recommend downloading the official datasheet and reviewing the detailed electrical characteristics and application information provided by the manufacturer. For technical inquiries or to discuss how this module can be integrated into your next power conversion project, please contact our engineering support team for a detailed consultation.
