R41D: Y2 Film Capacitor for Demanding SiC Topologies

Y Capacitors in EMI Filters

Y capacitors divert common-mode noise to protective earth or the enclosure and are therefore an important part of EMI filtering. In modern SiC topologies, high switching speeds increase not only the requirements for voltage withstand capability, but also for pulse current capability, thermal stability, and long-term reliability.

In addition to the required Y1 or Y2 safety classification and creepage and clearance requirements, the following properties are becoming increasingly important:

• High dV/dt capability and therefore high pulse current capability
• Low losses and high RMS current capability
• Stable performance under continuous high-frequency operation
• High THB resistance
• Long-term capacitance stability

R41D for High Dynamic Loads

The R41D series from YAGEO-KEMET is designed for applications where conventional safety capacitors can reach their performance limits. While conventional solutions are often specified for voltage slew rates of around 500V/µs, the R41D achieves specified values of up to 6000V/µs. This provides significantly greater headroom for the rapid voltage changes occurring in modern SiC circuits.

High RMS and pulse current capability, combined with optimized electrode structures, support reliable operation under repetitive high-frequency pulses. At the same time, compact package sizes allow space-efficient integration into high-power-density designs.

Balancing Capacitance and Leakage Current

When dimensioning Y capacitors, the desired common-mode attenuation must be balanced against the permissible leakage current. Increasing the capacitance can improve filtering performance, but it also increases leakage current at line frequency.

Temperature and humidity must also be considered during the design process. Especially in Y capacitors exposed to continuous high-frequency pulses, stable electrical characteristics over the entire operating lifetime are essential.

For High-Power SiC Applications

With the R41D, YAGEO-KEMET offers a compact Y2 capacitor solution for applications with high switching frequencies and dynamic electrical loads. Typical applications include on-board chargers, solar inverters, energy storage systems, EV charging stations, and three-phase UPS systems. CODICO supports the selection of suitable safety capacitors and the design of EMI filter solutions from the early development stage onward.

Why Is THB Resistance Important for Y Capacitors?

Temperature and humidity stress can significantly affect the long-term reliability of safety capacitors. High THB resistance helps maintain stable electrical characteristics under demanding environmental conditions and is therefore an important parameter when selecting Y capacitors for long-life power electronics.

CODICO offers a broad range of film capacitors for applications with demanding electrical and thermal requirements.

Your Contact Person

Roland Trimmel, CODICO’s specialist for capacitors, will be happy to support you with your project.