The attenuator is compatible with high-voltage automotive and industrial applications, helping engineers mitigate voltage spikes and oscillations to improve system reliability and efficiency.

The increasing adoption of SiC power modules in automotive and industrial applications reflects the growing demand for high-efficiency, high-voltage power modules. Operating at fast switching speeds and high voltages, SiC devices are inherently susceptible to voltage transients, high-frequency oscillations, and parasitic effects. These issues can generate leakage currents in the motor load, localized heating, and electrical stress, severely impacting module reliability and system efficiency. Integrating an RC attenuator mitigates these effects, and Melexis' initial measurements show that the RC attenuator can reduce switching losses by up to 50%. This contributes to improved system efficiency, optimized power density, enhanced thermal management, and reduced bill of materials (BOM) costs.

The Melexis RC attenuator is a silicon-based protection device that integrates both a resistor and a capacitor, providing high-voltage transient protection in a compact form factor. Designed for seamless mounting on high-voltage power modules, it follows standard integration approaches compatible with SiC devices. Its material and form factor enable precise integration with existing power module designs, improving manufacturability, reducing assembly complexity, and ensuring consistent performance across all devices.

Functionally, the RC attenuator mitigates the high-speed effects inherent in broadband semiconductors, including voltage transients and parasitic oscillations, while also improving electromagnetic compatibility (EMC). This prevents localized voltage surges that could stress SiC devices, enabling long-term reliability at higher switching frequencies. Its compact integration into power modules, with back-side metallization compatible with sintering and soldering processes, allows it to utilize the same heat dissipation channels as SiC components, minimizing hot spots and maintaining consistent module performance even at SiC junction temperatures up to 200°C.

With a breakdown voltage of 1640 V, it is suitable for traction inverters, on-board chargers, DC-DC converters, and other high-voltage industrial and automotive applications. Its design can reduce cooling and material requirements by decreasing heat dissipation for a given output power or, alternatively, allow for higher power density and optimize the number of transistors within the same thermal budget, while maintaining reliable electrical and thermal performance.

“Our silicon-based RC attenuator is the ideal solution for protecting and enhancing SiC power modules.” “By addressing voltage spikes, oscillation, and thermal challenges at the system level, we give designers the freedom to innovate, optimize performance, and reduce costs,” said Billy Ye, product line manager at Melexis. “While the MLX91299 is an exciting first step, it’s just the beginning of our new family of protection devices, which will continue to expand to meet the evolving needs of power modules and emerging power applications.”

The MLX91299 is the first device in the Melexis protection device family and has already undergone initial validation with selected customers. Samples are now available for evaluation. The family will be expanded to support a wide range of high-voltage applications.