As a core power conversion device in industrial automation systems, inverters are widely used in motor drives, pump and valve control, fan regulation, and other applications. Their basic architecture consists of rectification, filtering, inversion, braking, driving, and control units. The inverter unit, responsible for converting DC to AC, is critical to the overall efficiency, dynamic response, and reliability of the inverter system. The Insulated Gate Bipolar Transistor (IGBT) is the dominant switching device in the inverter bridge, and the balance between its conduction and switching losses is crucial.
HeroMicro's Trench FS IGBT Technology Architecture
HeroMicro has launched a new generation of Trench Field Stop (Trench FS) IGBT series based on trench gate field stop technology. Through multiple innovative designs, the product optimizes power performance:
1. Trench Gate Structure
Uses a vertical trench gate instead of a planar gate, increasing the effective gate width per unit area, enhancing transconductance (gm), and reducing on-state resistance (Ron);
Reduces gate charge (Qg), lowering drive losses and improving switching speed;
Optimizes electric field distribution, improving breakdown voltage stability.
2. Field Stop Layer
Introduces a highly doped N-type field stop layer between the N- drift region and the P+ substrate;
Effectively prevents the electric field from penetrating into the collector, enabling thinner silicon wafers (ultra-thin wafer processing);
Maintains high blocking voltage (e.g., 1200V) while significantly reducing drift region resistance, thereby lowering saturation voltage (Vce(sat)).
3. High-Density Device Design
Optimizes cell layout and termination structure to improve chip active area utilization;
Achieves higher current ratings in the same package size, increasing power density.
4. Carrier Engineering Optimization
Precisely controls doping profiles in the P-base, N-buffer, and field stop layers;
Optimizes carrier injection efficiency and distribution to achieve the best trade-off between conduction and turn-off losses;
Reduces tail current, minimizing turn-off losses and enhancing high-frequency switching performance.
Application Benefits in Inverters
1. Efficiency Improvement
Low Vce(sat) reduces conduction losses, especially under light to medium loads;
Low Eoff reduces high-frequency switching losses, improving overall system efficiency, particularly under PWM modulation;
Overall system efficiency can be improved by 1–3%, significantly reducing long-term operating energy consumption.
2. Thermal Design Optimization
Lower power loss means less heat generation, allowing for smaller heat sinks or lower fan power;
Increases power density, supporting compact inverter designs.
3. Enhanced Reliability
Trench gate structure provides better short-circuit withstand capability (typically supports >10μs);
Field stop technology improves avalanche energy tolerance;
Suitable for frequent start-stop cycles and overload conditions.
4. Improved Electromagnetic Compatibility (EMC)
Faster switching speeds require optimized gate driving and PCB layout;
Negative turn-off voltage (e.g., -5V to -8V) is recommended to suppress Miller effect;
Increasing gate resistance (Rg) or using active Miller clamps helps suppress dv/dt.
Typical Circuit Design Recommendations
Topology: Three-phase full-bridge inverter;
Driver IC: Single or dual-channel isolated drivers (e.g., 1ED series) are recommended to ensure drive capability and isolation voltage;
Freewheeling Diode: Pair with fast, soft-recovery anti-parallel diodes to optimize commutation;
Protection: Integrate DESAT detection, overcurrent protection, and temperature monitoring.
