Capacitors for DC Link Circuits
TDK presents the EPCOS CeraLink™, an innovative DC link capacitor for frequency converters. CeraLink™ is based on a PLZT ceramic material (lead lanthanum zirconate titanate) and covers a capacitance range from 1 µF to 100 µF at a rated voltage of 400 V DC. Another type has a rated voltage of 800 V DC and a capacitance of 5 µF.
The new CeraLink™ offers many benefits in the stabilization and filtering of DC link circuits of power converters - especially compared to conventional capacitor technologies. Thanks to a low ESL value of less than4 nH as well as a low ESR of less than 4 mΩ, the new capacitors are ideally suited for applications with high switching frequencies and rapid rise times. This includes converters for industrial and automotive electronics that operate with new fast-switching MOSFETS or IGBTs.
CeraLink™ can be produced with several commonly available terminal configurations, including low profile, SMD, solder pin and press-fit busbar types. Designs that can be integrated in semiconductor power modules are also possible. CeraLink™ is designed for temperatures between -40 and +125° C (also up to +150° C for short periods), making it suitable for SiC-based power modules as well. Compared to conventional MLCCs, CeraLink™ features a positive DC bias. Another benefit of the new capacitor is the very compact dimensions. Depending on the type, they range between 6.84 x 7.85 x 2.65 mm3 and 52.5 x 30.5 x 10.5 mm3.