Content last revised on February 26, 2026
An Engineer's Look at the FZ400R12KS4P Chopper IGBT Module
Optimizing High-Frequency Power Systems with Proven Technology and Simplified Assembly
The Infineon FZ400R12KS4P is a high-performance chopper IGBT module engineered to deliver a balanced combination of efficiency and reliability in dynamic, high-frequency applications. With its core specifications of 1200V and 400A, this module integrates Infineon's fast IGBT2 technology within a robust 62mm industrial standard housing. Key benefits include reduced switching losses for efficient high-frequency operation and a pre-applied Thermal Interface Material (TIM) to streamline manufacturing and enhance thermal performance. What is the primary advantage of its chopper configuration? It provides a single, controllable switch ideal for applications like DC-DC converters and brake choppers. For demanding industrial drives and power conversion systems where switching performance and thermal management are critical, the FZ400R12KS4P presents a technically sound and practical solution.
Key Parameter Overview
Decoding the Specs for High-Frequency Switching Performance
The technical specifications of the FZ400R12KS4P are tailored for robust performance in demanding power electronic systems. The following table groups key parameters by their functional area, providing a clear view of the module's capabilities. These values are extracted from the official datasheet and represent the component's performance under specified test conditions.
| Characteristic | Symbol | Condition | Value |
|---|---|---|---|
| Static Characteristics (IGBT) | |||
| Collector-Emitter Voltage | V_CES | T_vj = 25°C | 1200 V |
| Collector-Emitter Saturation Voltage | V_CEsat | I_C = 400 A, V_GE = 15 V, T_vj = 125°C | 2.10 V (typ.) |
| Gate-Emitter Threshold Voltage | V_GE(th) | I_C = 6.0 mA, V_CE = V_GE, T_vj = 25°C | 5.8 V (typ.) |
| Dynamic Characteristics (IGBT) | |||
| Turn-On Switching Energy | E_on | I_C = 400 A, V_CE = 600 V, T_vj = 125°C | 46 mJ (typ.) |
| Turn-Off Switching Energy | E_off | I_C = 400 A, V_CE = 600 V, T_vj = 125°C | 57 mJ (typ.) |
| Short Circuit Withstand Time | t_psc | V_GE ≤ 15 V, V_CC = 800 V, T_vj ≤ 150°C | 10 µs |
| Thermal & Mechanical Characteristics | |||
| Thermal Resistance, Junction to Case | R_th(j-c) | per IGBT | ≤ 0.080 K/W |
| Isolation Test Voltage | V_ISOL | RMS, f = 50 Hz, t = 1 min | 4.0 kV |
| Operating Junction Temperature | T_vj op | -40 to 150 °C | |
Application Scenarios & Value
Achieving System-Level Benefits in Industrial Power Conversion
For systems requiring precise and rapid control of high DC currents, such as the brake chopper circuit in a Variable Frequency Drive (VFD), the FZ400R12KS4P is an optimal choice. When a motor decelerates, the VFD's DC bus voltage rises. This module's job is to switch rapidly, diverting excess energy into a braking resistor to prevent an overvoltage fault. The "Fast IGBT2" technology inside ensures low switching losses (E_on = 46 mJ, E_off = 57 mJ), which is critical because brake choppers operate at high frequencies. Lower losses mean less heat generated per switching event, directly contributing to higher system efficiency and reliability.
Think of the trade-off between conduction and switching loss like choosing tires for a delivery vehicle. Hard, low-rolling-resistance tires are great for highway efficiency (low conduction loss), but poor for stop-and-go city traction (high switching loss). The FZ400R12KS4P is engineered like an advanced all-season tire, offering a balanced performance that works exceptionally well in applications with both continuous current flow and frequent switching, such as in high-power DC-DC converters and uninterruptible power supplies (UPS). For applications demanding even higher current handling within the same package and chopper configuration, the related FZ600R12KS4 offers a 600A capability.
Frequently Asked Questions
Engineering Queries on the FZ400R12KS4P
What is the direct engineering benefit of the pre-applied Thermal Interface Material (TIM)?
The pre-applied TIM eliminates a manual production step, ensuring a consistent and optimized thermal path between the module's baseplate and the heatsink. This reduces the risk of assembly errors like uneven application or contamination, leading to more predictable and reliable thermal performance across production units. What is the primary benefit of its pressure-contact design? Enhanced long-term reliability by eliminating solder fatigue.
How does the single-switch 'chopper' configuration (KS4) influence its application use compared to a half-bridge module?
The chopper configuration provides a single, high-side switch with an anti-parallel freewheeling diode. This topology is purpose-built for applications that require controlling power flow in one direction, such as boosting or bucking voltage in DC-DC converters or managing energy in brake chopper circuits. It is simpler and more cost-effective for these tasks than a half-bridge module, which is designed for creating an AC output waveform in motor inverters.
Technical Deep Dive
A Closer Look at the Fast IGBT2 and Thermal Design
The core of the FZ400R12KS4P is its "Fast IGBT2" silicon, a technology specifically tuned for high-frequency operation. In power electronics, there is an inherent conflict between low on-state voltage (V_CEsat) and fast switching speeds. The Fast IGBT2 is designed to find a sweet spot in this trade-off. By optimizing the carrier profile and gate structure, it achieves a relatively low V_CEsat of 2.1V at 125°C while keeping total switching energy under control. This makes it a superior choice over older IGBT technologies in applications where switching frequencies exceed the typical 2-4 kHz of standard motor drives.
This design choice can be compared to the engine tuning of a rally car. A drag racer's engine (analogous to an IGBT for low-frequency, high-current applications) is tuned for maximum power in a straight line, sacrificing agility. A rally car's engine, however, must provide strong acceleration and deceleration repeatedly, balancing raw power with responsiveness. The Fast IGBT2 is tuned like that rally engine, making it adept at the rapid on-off cycles found in switch-mode power supplies and brake choppers. The module's robust short-circuit withstand time of 10µs further underscores its suitability for rugged industrial environments where fault conditions can occur. For more details on effective heat dissipation, explore this guide on mastering IGBT thermal management.
To further leverage this performance, the module's construction focuses on thermal integrity. The integration of a pre-applied TIM is a significant value-add for volume manufacturing. It ensures a defined, low thermal resistance from the module case to the heatsink, a critical factor detailed by manufacturers like Infineon. This not only simplifies assembly but also reduces the performance variability that can stem from manual thermal paste application, directly impacting long-term system reliability.
For professional evaluation of this or any power module, it is essential to follow standardized procedures. A practical field guide on how to test an IGBT module with a multimeter can provide a baseline for incoming inspection and field diagnostics.
For engineering teams developing high-reliability power conversion systems, the FZ400R12KS4P offers a proven, well-documented solution. To discuss your specific application requirements or to inquire about this component, please contact our technical sales team for a detailed consultation.
