Infineon FS35R12W1T4: A Technical Review of the 1200V H-Bridge IGBT Module
Infineon FS35R12W1T4 1200V Four-Pack IGBT Module
Introduction and Core Highlights
The Infineon FS35R12W1T4 is a power IGBT module that integrates a full H-Bridge (Four-Pack) configuration into a single, compact EasyPACK™ 1B housing. This module’s primary value is its combination of a complete power stage with an integrated NTC thermistor, leveraging TrenchSTOP™ IGBT3 technology to offer a balanced performance profile. This integration simplifies both the power circuit layout and the system’s thermal management, enabling more streamlined and reliable designs for moderate-power applications.
- Core Specifications: 1200V | 35A | VCE(sat) (typ) 1.95V
- Key Advantages: Facilitates precise thermal monitoring via an integrated NTC, reduces stray inductance with a compact H-Bridge layout.
By providing a factory-assembled H-bridge, the FS35R12W1T4 helps engineers bypass the complexities of matching discrete components and optimizing gate drive layouts.
Download the Official FS35R12W1T4 Datasheet (PDF)
Technical Analysis of the H-Bridge Integration
The FS35R12W1T4 module’s defining feature is its Four-Pack configuration, which forms a complete H-Bridge. Housing all four IGBTs and their corresponding freewheeling diodes in one physical package significantly reduces the parasitic inductance between switches compared to a solution built from discrete components. Lower inductance minimizes voltage overshoots during high-speed switching events, which can enhance system reliability and potentially reduce the need for larger snubber circuits. This integrated approach simplifies the power-stage PCB layout, saving development time and board space.
Underpinning this module is Infineon’s TrenchSTOP™ IGBT3 technology. This generation of IGBTs is characterized by a balance between conduction losses, represented by the collector-emitter saturation voltage (VCE(sat)), and switching losses (Eon and Eoff). Think of the module’s thermal resistance as the width of a drainpipe for heat; a lower value allows heat to escape more easily. The Al2O3 substrate provides a low thermal resistance path (Rth(j-c) of 0.72 K/W per IGBT), ensuring efficient heat transfer to an external heatsink and preventing the device from overheating under load.
Optimized Application Scenarios
The specific characteristics of the FS35R12W1T4 make it a strong candidate for several power conversion applications:
- Small Motor and Servo Drives: The integrated H-bridge is the fundamental building block for driving DC motors or for one phase of a three-phase inverter, while the compact EasyPACK™ footprint is ideal for space-constrained drive housings.
- Uninterruptible Power Supplies (UPS): The 1200V blocking voltage provides a robust safety margin for DC bus voltages derived from rectified mains, and the H-bridge topology is essential for the DC-to-AC inversion stage.
- Solar Inverters: In smaller-scale solar installations, this module can serve as the core of the DC-AC inverter, with the integrated NTC ensuring safe operation under varying environmental conditions.
- Welding Power Supplies: The module’s switching characteristics are well-suited for the high-frequency inverters used in modern welding equipment.
Its blend of voltage rating, current handling, and integrated topology makes it a best match for power conversion systems requiring a compact H-bridge solution.
Key Specification Parameters for the FS35R12W1T4
| Absolute Maximum Ratings (Tvj = 25°C unless otherwise specified) | ||
|---|---|---|
| Parameter | Symbol | Value |
| Collector-Emitter Voltage | VCES | 1200 V |
| Continuous Collector Current @ TC=80°C | IC nom | 35 A |
| Repetitive Peak Collector Current (tP=1ms) | ICRM | 70 A |
| Gate-Emitter Voltage | VGES | ±20 V |
| Electrical & Thermal Characteristics | ||
| Collector-Emitter Saturation Voltage (IC=35A, VGE=15V, Tvj=25°C) | VCE sat | 1.95 V (Typ.) |
| Gate Threshold Voltage (IC=1.4mA, VCE=VGE, Tvj=25°C) | VGE(th) | 5.8 V (Typ.) |
| Thermal Resistance, Junction to Case (per IGBT) | RthJC | 0.72 K/W |
| Operating Junction Temperature | Tvj op | -40 to +150 °C |
| NTC Resistor Rated Resistance @ 25°C | R25 | 5 kΩ ±5% |
Engineer’s FAQ
- What is the primary benefit of the integrated NTC thermistor in the FS35R12W1T4?
- The integrated NTC provides a direct and accurate way to monitor the module’s substrate temperature. This feedback is critical for the system’s controller to implement over-temperature protection, preventing thermal runaway and improving the long-term reliability of the power semiconductors. The datasheet provides a complete resistance-temperature characteristic table for accurate calibration.
- What mounting considerations are important for the EasyPACK 1B package?
- The EasyPACK 1B is a baseplate-less module. It requires careful mounting to a flat, clean heatsink surface using a thermal interface material (TIM) to ensure low thermal resistance. The datasheet specifies a mounting torque for the screws to achieve the correct pressure without damaging the module. The integrated mounting clamps are designed to provide rugged and reliable contact.
- What is the maximum allowable case temperature (TC)?
- The datasheet specifies the maximum operating junction temperature (Tvj op) as 150°C. The maximum case temperature will depend on the power dissipation and the thermal resistance from junction to case (RthJC). Engineers must calculate this based on their specific operating conditions (current, voltage, switching frequency) to ensure the junction temperature never exceeds its limit.
- Can this module be used in hard-switching and soft-switching topologies?
- Yes. The TrenchSTOP™ IGBT3 technology and the co-packed Emitter Controlled 3 diode are engineered for a balanced performance that is suitable for both hard-switching applications like standard PWM inverters and resonant or soft-switching topologies where lower switching losses are a priority.
Enabling Compact and Reliable Power Design
The FS35R12W1T4 provides a robust engineering solution for designers needing a complete 1200V H-Bridge in a single component. By integrating the power stage and thermal sensing into the verified EasyPACK™ platform, this module allows engineering teams to focus on system-level innovation rather than on the complexities of discrete power device layout. This approach directly supports the development of more compact, reliable, and thermally-managed power conversion systems.