In the realm of power electronics, Insulated Gate Bipolar Transistors (IGBTs) play a pivotal role in controlling and managing high-power applications. However, the efficient functioning of IGBTs is often marred by transient voltage spikes and surges that can lead to their malfunction or even failure. To help engineers and designers mitigate these risks, Bourns offers a comprehensive line of Power TVS (PTVS) and TVS diodes. In this blog, we present some of the details presented in a Bourns application note that focuses on the importance of IGBT switching protection and how PTVS/TVS diodes can be leveraged to enhance IGBT reliability.

Understanding the Challenge

IGBTs are known for their ability to handle high-voltage and high-current applications, making them indispensable in various industries such as industrial automation, renewable energy systems, motor drives, and more. However, during IGBT switching events, such as turn-on and turn-off, the rapid changes in voltage and current can create voltage spikes and transients that might exceed the IGBT’s voltage rating.

These voltage spikes can result have dire consequences, and in the worst-case scenario, create an entire system breakdown. That’s why the need for reliable and robust protection mechanisms is paramount to ensure the longevity and efficiency of IGBT-based systems.

Why PTVS/TVS Diodes

Bourns offers a range of PTVS and TVS diodes that have the advanced capabilities to address the challenges posed by voltage transients in IGBT-based systems. Designed to act as “safety valves”, Bourns’ diodes operate by diverting excess voltage away from the IGBT and absorbing the transient energy, thereby safeguarding the IGBT and the entire circuit.

Insights from the Application Note

The application note delves into the technical aspects of PTVS/TVS diodes and how they can be effectively integrated into IGBT protection circuits. Below are some key takeaways from the paper:

1. IGBT Stress Factors: There can be various stress factors that IGBTs experience during switching events. These include voltage overshoots, undershoots, and slew rate limitations. PTVS/TVS diodes can effectively dampen these transient effects, preventing IGBT damage.
2. TVS Diode Selection: The application note provides guidance on selecting the appropriate TVS diode based on factors such as peak pulse power, clamping voltage, and energy handling capability. This ensures optimal protection tailored to the specific IGBT application.
3. Circuit Integration: Proper integration of PTVS/TVS diodes within the IGBT protection circuit is crucial. The application note outlines various circuit configurations, such as series and parallel connections, to maximize protection efficiency.
4. Layout Considerations: Efficient PCB layout is essential for maintaining the integrity of the protection circuit. The application note presents layout considerations that minimize inductance and optimize performance.
5. Thermal Management: PTVS/TVS diodes, like any electronic component, require effective thermal management. Techniques to manage heat dissipation and ensure the longevity of the diodes are also highlighted in the application note.

Conclusion

The reliability and performance of IGBT-based systems often relies on the effective management of transient voltage spikes during switching events. Bourns’ broad line of PTVS/TVS diodes provide an excellent solution to this challenge, ensuring the protection of IGBTs and thereby the overall system. By understanding the technical insights provided in Bourns’ application note, designers get the information they need to implement robust protection strategies that enhance the reliability, efficiency, and lifespan of their IGBT-driven applications. As technology continues to advance, solutions such as Bourns^® PTVS/TVS diodes pave the way for safer and more dependable high-power electronics across industries.